Decision #33/13 - Type: Workers Compensation
Preamble
The worker is appealing three decisions made by Review Office of the Workers Compensation Board ("WCB") in relation to his compensation claim for a myocardial infarction that occurred in the workplace on April 10, 2008. A hearing was held on September 27, 2012 to consider the matter. The hearing reconvened on January 17, 2013.Issue
Whether or not responsibility should be accepted for the coronary artery by-pass grafting surgery performed on July 29, 2011;
Whether or not the worker's permanent partial impairment award should be reduced by 50% due to a pre-existing condition; and
Whether or not a Medical Review Panel should be convened pursuant to subsection 67(4) of the Act.
Decision
That responsibility should not be accepted for the coronary artery by-pass grafting surgery performed on July 29, 2011;
That the worker's permanent partial impairment award should be reduced by 50% due to a pre-existing condition; and
That a Medical Review Panel should not be convened pursuant to subsection 67(4) of the Act.
Decision: Unanimous
Background
On April 10, 2008, the worker suffered a myocardial infarction ("MI") while performing lifting activities at work. His claim for compensation was accepted by the WCB and benefits and services were paid while the worker underwent treatment for his heart condition.
On September 8, 2010, a WCB medical advisor reviewed the worker's claim for the purposes of establishing a Permanent Partial Impairment ("PPI") award in relation to the April 10, 2008 MI. After considering both subjective and objective factors as per the methodology described in the WCB Permanent Impairment Rating Schedule, the WCB medical advisor determined that the worker's impairment resulting from his MI was 32.3%. He then noted that: "The significant coronary artery disease demonstrated on angiography at the time of stent placement in June 2008 approximately 6 weeks following the myocardial infarction equates to the presence of a major pre-existing condition for the purpose of PPI determination. In light of the same, the PPI rating is prorated by 50%..." The final recommended PPI rating was therefore 16.2% [32.3% x 0.5=16.2%]. The worker disagreed with the decision and an appeal was filed with Review Office.
On December 8, 2010, Review Office confirmed that the PPI rating had been correctly calculated at 16.2% and that it reflected the percentage of total body impairment resulting from the effects of the work-related MI. Review Office noted that the worker's PPI award was calculated using the methodology described in the WCB's Permanent Impairment Rating Schedule and using The American Medical Association ("AMA") Guidelines to the Evaluation of Permanent Impairment, 6th Edition.
On January 19, 2011, the worker's treating cardiologist wrote the WCB with an update as to the worker's medical status. In particular, the cardiologist stated:
There seems to be some confusion and debate about the presence or absence of a "pre-existing condition" pertaining to this patient's heart problems. Your letters stated that "medical information obtained indicated that you had silent coronary artery disease" and that "the medical advisor was of the opinion that there was evidence to support that the worker had pre-existing, yet silent coronary artery disease". It is further stated that "although you had no symptoms, the disease existed prior to your myocardial infarction". I beg to disagree with those remarks. The remarks are simply opinion and are not based upon factual evidence. In fact, there was no evidence of significant underlying ischemic heart disease prior to this patient's MI in April 2008. If such evidence exists, I am not aware of it and neither is the patient's family physician. Your comment that "the worker had some degree of diffuse coronary artery disease prior to the workplace incident" is disingenuous and is simply an assumption. If you are assuming that there was coronary artery disease before the 10th of April 2008, then to what degree was it present? How long had it been present? Please recall that this patient had been a non smoker for 13 years prior to his event, had never had hypertension, was not diabetic and had no family history of IHD in first degree relatives. According to his GP, his pre-infarction cholesterol status had not been sufficiently high to warrant primary prevention, in advance of his MI in April 2008.
My conclusions, having gone over all of the evidence and having looked at this patient's coronary angiograms in detail myself, is that [the worker] sustained a work related myocardial infarction in April 2008, after which he has been completely disabled. Contrary to the views and opinions offered by the WCB and its consultants, there was in fact no evidence for significant obstructive coronary artery disease before this event. [The worker] continues to be disabled because of numerous issues, including his cardiovascular performance, medication effects, as well as anxiety/depression…Because of poor exercise performance on treadmill testing, we will be repeating further objective studies to look at his ongoing coronary stability, either with a repeat nuclear perfusion study or a stress echocardiogram. If he has new ischemia identified on those studies and/or continues to be substantially debilitated by chest discomfort and low stamina, then repeat coronary angiography will be done with a view to possible CABG. Finally, I would also comment that I believe that the ongoing stress related to the lack of reconciliation pertaining to his claim, is undoubtedly adding to his ongoing coronary risk.
On February 2, 2011, the worker requested an MRP on the basis that there was a difference of medical opinion between his treating cardiologist and WCB medical consultants as to whether or not he had a pre-existing condition prior to his MI in April 2008 and that this had a bearing on the calculation of his PPI award.
On March 9, 2011, the worker was seen at the WCB's office for a reassessment of his PPI. It was concluded from the assessment that: "The calculated PPI is 30.6%. [The worker], based on angiographic findings following the myocardial infarction, likely had a significant pre-existing process of atherosclerotic plaque formation. The cause of the April 2008 myocardial infarction would involve plaque instability and plaque rupture with subsequent thrombosis in the LAD. For the purpose of a PPI evaluation, this would be considered a major pre-existing/co-existing condition, which results in a prorating of the calculated PPI by 50%. The final PPI is, therefore, 30.6% x 0.5 = 15.3% whole person impairment."
On April 6, 2011, the treating cardiologist met with two WCB medical consultants who performed the PPI assessment of March 9, 2011 to clarify medical matters pertaining to the worker's cardiac impairment. In a note to file dated May 18, 2011, the WCB medical consultants stated:
"During our April 6, 2011, meeting with the treating cardiologist, the pathophysiology underlying the occlusive thrombus in the mid LAD and resultant myocardial infarction was discussed. The treating cardiologist agreed with our impression that the thrombus in the mid LAD likely occurred in relation to a significant pre-existing process that involved atherogenic plaque formation and plaque instability, culminating in plaque rupture and occlusive thrombus. The issue of rating the pre-existing atherogenic process involving [the worker's] mid LAD as either major or minor for the purpose of the PPI determination was also discussed with the treating cardiologist, who indicated that he did not have experience in the cardial impairment rating process. In light of the above, and insofar as a contextual PPI framework is a required factor in determining whether a pre-existing condition is major or minor, the cardiologists' opinion on this matter was not elicited."
In a decision dated May 24, 2011, the worker was advised that there was no differing medical opinion(s) that would warrant the convening of an MRP. The claims supervisor stated that the WCB healthcare consultants met with the treating cardiologist and the cardiologist acknowledged and agreed that there was a pre-existing process characterized by plaque formation. This plaque formation and plaque instability culminated in plaque rupture and the resulting heart attack. On June 9, 2011, the worker appealed the decision to Review Office.
On July 26, 2011, the WCB was informed that the worker had been taken to a local hospital facility via ambulance because of chest pain. On July 29, 2011, the worker underwent the following surgical procedures:
- Left heart catheterization, selective coronary angiography.
- Right iliac angiography.
- Intra-aortic balloon pump insertion for refractory angina.
With respect to the left main coronary artery, the surgeon noted: "Severe 90% ostial and left main disease extending into the mid portion of the body of the left main. Significant pressure damping. The patient developed chest pain with ST elevation in lead 1." With respect to the left anterior descending artery, the surgeon noted: "Type III LAD, stent in LAD patent, stent in diagonal has moderate ISR about 40-50% in its proximal portion."
On October 28, 2011, a WCB medical advisor and the WCB senior medical advisor reviewed the hospital reports to determine whether the worker's hospitalization in July and coronary bypass surgery were related to the effects of his compensable injury. The medical advisors' opinion was as follows:
[The worker's] 2008 claim was accepted for a myocardial infarction (heart attack) which occurred at the workplace on April 10, 2008, specifically in relation to a blockage (occlusion) of the left mid anterior descending coronary artery (mid LAD), termed the culprit artery.
While [the worker] was previously asymptomatic (i.e. no prior reported symptoms of heart disease), the coronary angiogram of April 11, 2008, demonstrated (in addition to the LAD lesion), evidence of a pre existing multi-vessel atherosclerotic process, as evidenced by:
· Right coronary artery 50-60% proximal stenosis
· Right coronary artery 50% mid segment stenosis
· Left coronary artery less than <25% ostial stenosis
· Left anterior descending coronary artery occluded
· Left anterior descending coronary artery, 1st diagonal branch 40% proximal stenosis with 80% stenosis beyond
· Left coronary artery ramus 50% ostial stenosis and 75% proximal stenosis
· Left circumflex coronary artery obtuse marginal branch 70% ostial stenosis
Over the past three years, there has been significant progression of the pre-existing atherosclerotic process in some of the coronary vessels, a matter substantiated as follows:
· Whereas the April 11, 2008, coronary angiogram there was noted to be a <25% ostial stenosis of the left coronary artery, at the most recent coronary angiogram of July 29, 2011, there was reported to be 90% obstruction at the ostium (described as severe) with "disease extending into the mid portion of the body of the left main."
· Whereas the June 2, 2008 coronary angioplasty a stent was placed in the left anterior descending coronary artery diagonal branch (not representing the culprit artery), at the most recent coronary angiogram of July 29, 2011, there was noted to be a 40-50% restenosis present.
The aforementioned progression of the pre existing multi-vessel atherosclerotic is accounted for in relation to the natural history of the atherosclerotic process that existed prior to April 10, 2008. The progression of the pre accident multi-vessel atherosclerotic process would not have been materially affected by the April 10, 2008 myocardial infarction involving the mid LAD.
In relation to a recent episode of chest pain, a July 29, 2011, coronary angiogram noted a patent (open/unobstructed) stent in the mid portion of the LAD. That is, the coronary artery that had been occluded during the April 10, 2008 heart attack was patent. Rather, the recent episode of chest pain and need for bypass grafting was in relation to stenosis/obstruction at a different part of the left coronary artery (the ostium), where there had been non-accident related progression of the non accident related atherosclerotic process, as evidenced by <25% stenosis in 2008 vs 90% stenosis at July 29, 2011.
In summary, the LAD occlusion of April 10, 2008, for which the WCB accepted responsibility was not the cause of the recent chest symptoms or the need for the recent hospitalization and bypass surgery. Rather, these procedures were required because of the progressive nature of the pre existing atherosclerotic process involving coronary arteries other than the mid LAD, unaffected by effects of the April 10 2008 infarction.
In a decision dated November 1, 2011, the worker was advised that the WCB was unable to accept responsibility for his July 2011 coronary bypass heart surgery, as the cause and need for the surgery was not related to his compensable injury. The decision was based on the opinion expressed by the WCB medical consultants on October 28, 2011. The case manager noted that in the WCB's opinion, the worker's pre-existing condition was unaffected by the original MI of April 10, 2008. On January 3, 2012, the worker appealed this decision to Review Office and made reference to the opinion outlined by his treating cardiologist dated January 19, 2011.
In a memo dated November 9, 2011, the WCB senior medical advisor calculated the worker's PPI rating at 36%. The medical advisor stated:
In summary, notwithstanding that [the worker] did not have pre-existing symptoms of coronary artery disease, the April 11, 2008 angiogram/angioplasty documented thrombotic occlusion of the mid LAD likely occurred as the culmination of a relatively longstanding atherogenic process affecting that artery, a matter substantiated by the April 11, 2008 angiogram documented presence of probable atherosclerotic based stenosis in other aspects of [the worker's] coronary circulation and the August 25, 2009 opinions of the angiographer. The probable pre-existing atherogenic process affecting the mid LAD is considered major for the purpose of the PPI assessment, resulting in a pro-rating of the calculated PPI by 50%. The final PPI stemming from the March 9, 2011 examination is therefore 36% x 0.5 = 18% whole person impairment.
On November 28, 2011, Review Office determined that the worker's PPI rating should increase from 16.2% to 18% based on the recommendation made by the senior WCB medical advisor dated November 9, 2011. Review Office also determined that a MRP would not be convened based on subsection 67(4) of The Workers Compensation Act (the "Act"). Review Office stated that there was no evidence on file at the current time that the cardiologist had a differing opinion from that as expressed by the WCB senior medical advisor. On November 9, 2011, the WCB senior medical advisor issued correspondence to the worker's cardiologist, explaining his understanding of the worker's coronary artery disease, and the evidence of its existence prior to April 10, 2008, and the cardiologist was requested to respond, should he have a different opinion. At the time of the Review Office decision, he had not responded. Review Office noted that it was the impression of the WCB senior medical advisor, after a meeting with the cardiologist, that no difference of medical opinion on this matter existed.
The worker provided Review Office with an October 5, 2011 Stress Test to determine if the test results would increase his current PPI rating of 18%. On December 15, 2011, Review Office advised the worker that a WCB medical advisor reviewed the new medical evidence and it was determined that the stress test results were non-diagnostic and did not add further information which would likely alter the decision regarding his PPI. Review Office therefore found no reason to alter the PPI rating of 18%.
On February 29, 2012, Review Office determined that no responsibility could be accepted for the coronary by-pass grafting surgery which the worker underwent on July 29, 2011. Review Office held that the WCB's responsibility for the worker's cardiac complaints was limited to the infarct in the LAD which occurred on April 10, 2008 and did not extend to the progressive coronary artery disease which had been proven through repeated medical investigations. At the time of his most recent surgery, the surgeon described the stent which had been inserted in the LAD on April 11, 2008, for treatment of his compensable myocardial infarction as being patent or open. Thus, it was Review Office's opinion that the surgery performed on July 29, 2011 could not reasonably be associated with the compensable infarction which occurred on April 8, 2008.
On September 27, 2012, a hearing was held at the Appeal Commission to consider the worker's appeal of the decisions made by Review Office. The September 27, 2012 hearing was adjourned as the appeal panel wished to obtain further information from the worker's treating cardiologist. A report from the cardiologist was later received dated November 9, 2012 and a copy was provided to a WCB senior medical advisor for comment. Both the cardiologist's report and a response from the WCB senior medical advisor dated December 3, 2012 were forwarded to the worker for information purposes and the hearing reconvened on January 17, 2013.
Reasons
Applicable Legislation and Policy:
The Appeal Commission and its panels are bound by The Workers Compensation Act (the “Act”), regulations and policies of the Board of Directors.
Under subsection 4(1) of the Act, where a worker suffers personal injury by accident arising out of and in the course of employment, compensation shall be paid to the worker by the WCB. Subsection 4(1) provides:
Compensation payable out of accident fund
4(1) Where, in any industry within the scope of this Part, personal injury by accident arising out of and in the course of the employment is caused to a worker, compensation as provided by this Part shall be paid by the board out of the accident fund, subject to the following subsections.
WCB Policy 44.10.80.40, Further Injuries Subsequent to a Compensable Injury (the “Further Injuries Policy”) applies to circumstances where a worker suffers a separate injury which is not a recurrence of the original compensable injury, but where there may be a causal relationship between the further injury and the original compensable injury. The Further Injuries Policy provides:
A further injury occurring subsequent to a compensable injury is compensable:
(i) where the cause of the further injury is predominantly attributable to the compensable injury; or
(ii) where the further injury arises out of a situation over which the WCB exercises direct specific control; or
(iii) where the further injury arises out of the delivery of treatment for the original compensable injury.
A further injury which occurs as a result of actions (for example, medical treatment) known by the worker not to be acceptable to the WCB is not compensable.
Payment of compensation for an impairment is provided for under section 38 of the Act, which reads as follows:
Determination of impairment
38(1) The board shall determine the degree of a worker’s impairment expressed as a percentage of total impairment.
WCB Policy 44.10.20.10, Pre-Existing Conditions (the "Policy") describes how a pre-existing condition may affect entitlement to benefits. With respect to a PPI, the Policy provides as follows:
3. IMPAIRMENT AWARD ELIGIBILITY
If a worker is injured as a result of a compensable accident and the injury results in a rateable impairment, the existence of a pre-existing condition will not negate the worker's entitlement to an impairment award. However, if the worker's impairment (whether caused by the compensable accident or a surgical intervention made necessary by the compensable accident ) is an enhancement of a pre-existing but non-compensable impairment, the worker is eligible for an impairment award based on the difference between the new combined rating and the rating assigned to the pre-existing condition.
4. ASSIGNED RATING FOR PRE-EXISTING CONDITIONS
When it is reasonable to do so, the assigned rating for the pre-existing condition will be based on the impairment rating schedule adopted by the WCB. However, when this is not practical, the assigned rating will be determined as follows:
(a) A pre-existing condition which is deemed to be minor will be assigned a 0% rating. (b) A pre-existing condition which is deemed to be major will be assigned a rating equivalent to 50% of the total combined impairment rating. The provisions of the Act which relate to the worker's request for an MRP are subsections 67(4) and 67(1). Subsection 67(4) provides: Reference to panel on request of worker 67(4) Where in any claim or application by a worker for compensation the opinion of the medical officer of the board in respect of a medical matter affecting entitlement to compensation differs from the opinion in respect of that matter of the physician selected by the worker, expressed in a certificate of the physician in writing, if the worker requests the board, in writing before a decision by the appeal commission under subsection 60.8(5), to refer the matter to a panel, the board shall refer the matter to a panel for its opinion in respect of the matter. Subsection 67(1) defines opinion as "a full statement of the facts and reasons supporting a medical conclusion." Worker's position: The worker was self-represented at the hearing. He provided the panel with a very extensive and detailed 58 page written submission (subsequently supplemented by an 11 page addendum), which was reviewed at the hearing. The worker also responded to questions posed by the panel members during the course of the two hearing dates. The worker's submission addressed a variety of points regarding his WCB claim and the matters being appealed. Overall, his position on the three issues before the panel can be briefly summarized as follows: Of course, these summaries do not capture the particulars of the worker's arguments which were reviewed and discussed in detail at the hearing. They are only intended to provide a brief summary of the worker's position. Analysis: 1. Whether or not responsibility should be accepted for the coronary artery by-pass surgery performed on July 29, 2011. The first issue before the panel concerns the worker’s entitlement to WCB benefits in relation to July 2011 CABG surgery. In order for the worker’s appeal to be successful, we must find that the need for the surgery arose as a result of his compensable injury. On a balance of probabilities, we are not able to make that finding. The worker's submission was that he suffered unstable angina which resulted in triple bypass CABG surgery followed by a second surgery as a result of internal bleeding. All three of the stents that were implanted as a result of his April 2008 MI were circumvented during the CABG surgery and it was submitted that therein lay the causal relationship. The worker's position was that since the time of his MI, the CABG has always been on the horizon. Although the MI resulted in having three stents put in place, these were eventually circumvented by the CABG. It was submitted that the worker's heart suffered more than normal damage due to the unusually long time (18 hours) that his left anterior descending coronary artery ("LAD") was 100% blocked before his emergent angioplasty. As a result, it was submitted that there was a causal relationship between the CABG surgical procedure and the compensable injury. When making our decision, the panel must rely on the available medical evidence. In this case, the only medical opinion on file regarding the causal relationship between the April 2008 compensable injury and the CABG surgery is the October 28, 2011 opinion jointly authored by the WCB medical advisor and the WCB senior medical advisor. In it, they state: In summary, the LAD occlusion of April 10, 2008, for which the WCB accepted responsibility was not the cause of the recent chest symptoms or the need for the recent hospitalization and bypass surgery. Rather, these procedures were required because of the progressive nature of the pre-existing atherosclerotic process involving coronary arteries other than the mid LAD, unaffected by the effects of the April 10, 2008 infarction. We acknowledge the worker's submission that the two WCB medical advisors do not have specialized training in cardiology, but the panel finds that this does not invalidate their opinion. Even though they are not cardiologists, they have extensive medical training which would include education on matters related to the cardiovascular system. They also have access to extensive resource material which would enable them to further investigate medical matters. In the circumstances, the panel accepts their opinion as being valid. At the hearing, the worker was asked whether he could refer the panel to any contrary medical opinion which would support that there is a causal link between the CABG and the effects of the April 2008 compensable injury. He acknowledged that he could not. It is therefore the panel's decision that there is no causal relationship between the compensable injury and the July 2011 CABG and responsibility for the CABG surgery should not be accepted by the WCB. The worker's appeal on this issue is dismissed. 2. Whether or not the worker's permanent partial impairment award should be reduced by 50% due to a pre-existing condition. The second issue concerns whether or not the worker's partial impairment award should be reduced on account of a pre-existing condition. The Policy provides that where a worker has a pre-existing condition which is deemed to be major, a 50% rating will be assigned to the pre-existing condition, the end result of which will be to reduce to the total PPI rating by 50%. Accordingly, in order for the worker's appeal on this issue to succeed, the panel must find that the worker did not have a major pre-existing condition. On a balance of probabilities, we are not able to make that finding. At the hearing, the worker strongly argued that there is a critical difference between the terms pre-existing process and pre-existing condition. As the WCB senior medical officer described the worker's condition as a "significant pre-existing process that involved atherosclerotic plaque formation, plaque instability and plaque rupture," the worker submitted that the requirement for a pre-existing condition under the Policy was not met. The worker maintained this argument despite the December 16, 2011 memo to file by the WCB senior medical officer which clarified that his use of the terms "pre-existing condition" and "pre-existing process" were as synonyms. In making his argument, the worker relied on a January 19, 2011 letter from his cardiologist, a portion of which is outlined earlier under the background portion of this decision and which opined: "Contrary to the views and opinions offered by the WCB and its consultants, there was in fact no evidence for significant obstructive coronary artery disease before this event." The appeal hearing was initially convened on September 27, 2012, but was adjourned to permit the panel to ask the worker's cardiologist for clarification of his position. According to correspondence on file, the WCB senior medical officer had spoken with the cardiologist in April 2011 and they had reached a consensus regarding the presence of pre-existing atherogenic plaque formation and plaque instability, culminating in plaque rupture and occlusive thrombus. The WCB senior medical officer later summarized their discussions in writing and sent a copy of his memorandum to the cardiologist with a request to comment if he held a different opinion on the matter of an atherogenic condition involving the worker's left mid LAD prior to the April 2008 MI. No response was ever received from the cardiologist. The hearing was adjourned to obtain confirmation from the cardiologist regarding his views on this question. By letter dated November 9, 2012, the cardiologist advised the panel as follows: With respect to my letter dated January 19, 2011, page 2 paragraph 2, I had stated that "there was in fact no evidence for significant obstructive coronary disease before this event". This statement may have seemed naïve, but I was trying to apply plain truth in terms of my response. The word "evidence" in my mind means the objective presence of an abnormality consistent with the underlying disease obtained prior to the event itself. From that perspective, my assertion was correct. [The worker] had never had an abnormal routine stress test or as far as I understand, an abnormal routine EKG. He had never had a nuclear perfusion study or a cardiac echo prior to his event and he certainly hadn't had a coronary angiogram or a CT scan of his coronary arteries. [The WCB senior medical advisor] advised me, during our informal meeting April 6, 2011, that such objective evidence 'was not necessary' from the WCB perspective, to satisfy the presence of a pre-existing condition. In other words, on the basis or (sic) probabilities, underlying coronary atherosclerosis was almost certainly present before the acute event. This retrospective argument has no easy rebuttal. The reality is that coronary atherosclerosis almost certainly begins at a very early age, perhaps in late teens or early twenties based on past research and academic study. The reality is that a majority of us by middle age, will have some degree of coronary atherosclerosis and in many cases this is asymptomatic without any outward manifestations, although I would point out that moderate to severe coronary obstructive atherosclerosis could likely be picked up on screening studies such as routine treadmill testing or nuclear perfusion testing even in an asymptomatic patient. I would also point out that the presence of a ruptured plaque in the presence of acute MI does not necessarily imply that the pre-existing plaque was either moderate or severe. It is well known by Cardiologists and researchers that some patient's may have acute MI, following the rupture of a mild plaque only. Nevertheless, we understand that coronary atherosclerosis is in fact a chronic condition. In that sense, based on the WCB interpretation of probabilities, it seems that many of us by middle age would be defined as having a "pre-existing condition" if we developed an acute heart attack (MI) in the workplace. Having said that, there are rare occasional cases whereby an acute heart attack (MI) may occur acutely in response to trauma which has occurred in the workplace independent of the atherosclerosis condition. Nevertheless, for the purposes of clarification, my challenge to the assertion of a pre-existing condition in [the worker's] case was essentially directed at the absence of any objective evidence/testing prior to his heart attack that indicated the presence of coronary atherosclerosis. The panel finds that, once all labels and semantics are set aside, there is consensus among the medical experts. Both the worker's cardiologist and the WCB senior medical advisor acknowledge the presence of coronary atherosclerosis prior to the MI of April 10, 2008. Regardless of whether the coronary atherosclerosis is labeled a "process" or a "condition" and regardless of whether or not it was detected/diagnosed prior to the MI, the panel is satisfied that the earlier presence of coronary atherosclerosis meets the "pre-existing condition" requirement contained in the Policy. The Policy provides for a 50% reduction in a PPI award to account for non-work related factors which have significantly contributed to a compensable injury. In the panel's opinion, regardless of whether it was called a process or a condition, the coronary atherosclerosis plaque was present in the worker's mid LAD and it was a causative factor which led to his April 2008 MI. The panel does not agree with the worker's assertion that the unpacking of boxes was such an onerous task that the activity alone caused him to suffer the MI. It was a combination of the pre-existing coronary atherosclerosis and the work-related activity which led to the compensable injury. With respect to the question of whether the pre-existing condition was minor or major, the medical opinions on file from a WCB medical consultant and the WCB senior medical advisor characterize the pre-existing condition as major. The worker's cardiologist does not opine on whether the condition was major or minor. At most, he points out that: "the presence of a ruptured plaque in the presence of acute MI does not necessarily imply that the pre-existing plaque was either moderate or severe." The panel notes the worker's statement that his LAD was 100% blocked before his emergent angioplasty. This indicates that the degree of plaque occlusion was very severe. In the circumstances, the panel finds that it is appropriate to characterize the pre-existing condition as major, and accordingly, the 50% reduction to the PPI award as set out in the Policy applies. The worker's appeal on this issue is dismissed. 3. Whether or not a Medical Review Panel should be convened pursuant to subsection 67(4) of the Act. The final issue before the panel deals with entitlement to an MRP. In order for the worker's appeal on this issue to succeed, the panel must find on a balance of probabilities that the medical opinion of a medical officer of the WCB differs from the opinion of the worker’s treating physician in respect of a medical matter affecting entitlement to compensation, within the meaning of subsections 67(4) and 67(1) of the Act. We are unable to make that finding. As outlined earlier in this decision, the panel finds that coronary atherosclerosis was present in the worker's mid LAD prior to his April 2008 MI. This was the pre-existing condition which triggered the 50% reduction in the worker's PPI award. The coronary atherosclerosis was characterized by the WCB senior medical advisor as a pre-existing process/condition. The worker's position is that his cardiologist has given a differing opinion. We do not agree with this position. In the panel's view, all that the worker's cardiologist says is that the plaque had not been formally confirmed by testing and diagnosed prior to the April 2008 MI. The cardiologist does not deny its presence prior to the MI. In his November 9, 2012 letter to the Appeal Commission, he states: "For the purposes of clarification, my challenge to the assertion of a pre-existing condition in [the worker's] case was essentially directed at the absence of any objective evidence/testing prior to his heart attack that indicated the presence of coronary atherosclerosis" (emphasis in original). In the panel's opinion, the lack of formal confirmation of the plaque or the existence of a diagnosis prior to the MI is not a matter that affects benefits. Application of the Policy would only have been affected if the cardiologist gave the opinion that there was no plaque present prior to the MI. He does not say this. The panel therefore finds that there is no difference in opinion regarding a medical matter affecting entitlement to compensation. As such, an MRP should not be convened pursuant to subsection 67(4) of the Act. The worker's appeal on this issue is dismissed.
Panel Members
L. Choy, Presiding OfficerA. Finkel, Commissioner
P. Walker, Commissioner
Recording Secretary, B. Kosc
L. Choy - Presiding Officer
Signed at Winnipeg this 12th day of March, 2013