When Is a Heart Attack a Heart Attack?
Right up until the 1960s no specific treatment for heart attack existed; patients were simply advised to go home and rest in bed. Today, although our understanding and treatment of what’s technically called myocardial infarction (MI) has come a long way, diagnosis is still not straightforward. For insurers, problems surrounding heart attack definitions can make underwriting Critical Illness cover difficult for such “events”.
The Universal Definition of Myocardial Infarction, published in 2007, introduced a clinical classification of different types of MI.1 In particular it recognized a type 2 infarction where the ischaemia is induced by an imbalance of blood supply and demand, rather than an acute occlusion of the coronary artery.
Since 2007, even more sensitive techniques have been introduced: high sensitivity troponin assays, which are able to detect very small increases, were introduced around 2010. Use of these tests can reclassify patients presenting with chest pain from acute coronary syndrome to MI. This reclassification, however, does not seem to have an impact on outcomes and, in one study, only a third of the reclassified patients had a type 1 MI.2
The highly sensitive troponin assays do have a role in “ruling out” MI, however - particularly in patients presenting with atypical chest pain symptoms.
MI and impairment
Growing awareness of the importance of rapid reaction to incipient or early coronary artery occlusion has made it standard practice for patients presenting with chest pain to be fast-tracked and, if found likely to be suffering from acute ischaemic chest pain, to be taken straight to an angiographic suite and have coronary intervention that will limit or avoid ischaemic damage.
Often no ventricular damage results and the coronary artery is revascularized, preventing future ischaemia. This is the favoured outcome for the medical profession. However, it is not uncommon in this situation for there to be an elevation of cardiac biomarkers. In the setting of ischaemia, this would be defined as a MI, despite the lack of residual impairment.
A number of potential problems arise when providing Critical Illness cover for heart attack. Many of the older definitions require the presence of criteria that may not be measured or recorded during the rapid triage of patients with chest pain. Strict adherence to these criteria may result in valid claims being declined, to the disadvantage of the client and potential reputational damage to the insurance company.
On the other hand, Critical Illness products were developed to provide financial support to people who suffer serious and usually life-threatening disease with resultant long-term impairment. At the time the products first appeared, most MIs would have fallen into this category, but with increased sensitivity of biomarkers and imaging, and the availability of rapid interventions, often little or no clinical consequences follow acute ischaemic events.
Tiered products are used in some markets to avoid inappropriately high payouts for heart attacks with minimal or no resultant impairment. Different levels of severity are defined, which often include the requirement for impaired ventricular ejection fraction or regional wall abnormality. These levels are used to determine percentage payouts.
Clinical practice has changed and clinical heart attack definitions have also evolved to include very minor myocardial damage. The ideal management of a heart attack is prevention, and for many years primary prevention initiatives have reduced the incidence of cardiovascular disease.
At the same time, improvements in the early assessment and management of heart attack have dramatically improved outcomes for those patients who reach hospital. Commonly, timely intervention limits or eliminates significant myocardial damage. Critical Illness definitions and claims assessments do need to adapt to these clinical changes for valid claims to be admitted. At the same time, claim exposure to minor ischaemic events needs to be controlled if cover is to remain affordable.
- Thygesen, K., et al., Universal Definition of Myocardial Infarction. Circulation, 2007. 116 (22): p. 2634 - 2653.
- Shah, A. S. V., et al., High-sensitivity troponin in the evaluation of patients with suspected acute coronary syndrome: a stepped-wedge, cluster-randomised controlled trial. The Lancet, 2018. 392 (10151): p. 919 - 928.