• Cardiac rehabilitation
• Acute myocardial infarction
• Quality and outcomes of care

The past several decades have seen a marked improvement in outcomes for patients with myocardial infarction (MI). New drug and device discovery, coupled with high-quality randomised trials, have provided clinicians with an armamentarium of evidence-based treatments for MI. MI care is also the focus of numerous regional and national quality improvement efforts, and MI care processes and outcomes are commonly used as measures of overall hospital quality. As a result, treating a patients with MI has become structured and protocoled in many hospitals. Patients with MI receive a common package of interventions and medications and have generally benefited with improved survival and avoidance of recurrent ischaemic events.1

Despite this success, MI remains a feared diagnosis for patients that can have long-term implications for health and quality of life (QOL). Available treatments for MI, and the clinical trials that bring them to market, are primarily focused on reduction of cardiovascular mortality, MI and stroke. The impact of MI on patient-reported outcomes (PROs) such as angina and QOL is often not assessed in trials or examined only in secondary analyses. Interventions specifically targeted to improve QOL, such as cardiac rehabilitation, are underused. To address this lack of focus on PROs, clinicians and researchers have developed a variety of measures to quantity symptom burden and QOL, some designed specifically for patients with cardiovascular disease. Instruments such as the Seattle Angina Questionnaire, the Rose Dyspnea Scale and the Kansas City Cardiomyopathy Questionnaire have improved our understanding of the impact of cardiovascular disease on patients. There is increasing acceptance of PROs both as valid endpoints for clinical trials and as meaningful representations of patient experience and well-being. However, implementing PROs in clinical practice, and targeting QOL with specific treatments, remains challenging.

In this context, the study by Dr Munyombwe and colleagues provides important insights into the trajectory of QOL after MI.2 This large retrospective analysis of 9566 patients treated at 77 hospitals in England assessed QOL using the EuroQol-5D, Non-ST segment elevation myocardial infarction (EQ-5D) during the year following MI. Patients with MI commonly reported problems with pain, mobility and performance of routine activities. On average, QOL improved steadily after MI, but these gains were not seen uniformly. The study used latent growth class analysis to cluster patients according to QOL trajectory and identified a substantial minority for whom QOL did not improve (22.1%) or got worse (9.8%).

The factors associated with poorer baseline QOL and non-improving QOL were similar to those predicting worse long-term clinical outcomes in prior studies: advanced age, presentation with NSTEMI, higher burden of comorbid conditions, prior MI and prior revascularisation.3 These patients are at highest risk for angina and recurrent cardiovascular events that degrade QOL. It is more challenging to explain the poorer QOL experienced by women compared with men. This study joins a growing body of literature characterising gender disparities in MI care; women with MI are underdiagnosed, undertreated and have worse clinical outcomes. Women are more likely to present with ‘atypical’ symptoms of MI, and perhaps the disparity in long-term QOL relative to men may be partially explained by a differing profile of symptoms in the post-MI period.4 However, given that women are a large proportion of our contemporary MI population (approximately 25% in this study and over 50% in some older populations), it is no longer appropriate to consider women’s experience with MI to be ‘atypical’. Interventions to improve MI clinical outcomes and QOL should specifically consider how systemic bias related to gender may impact care delivery and outcomes.5 While race was not identified in this study as associated with poorer QOL, prior studies have also described racial disparities in the treatment and outcomes of MI.6

Use of a generic health-related QOL index, the EQ-5D, is both a strength and weakness of this study. Importantly, the EQ-5D identifies deficits that may not be assessed in a disease-specific QOL measure or in a standard postdischarge clinic visit. At 12 months, patients reported frequent problems with performance of routine activities (38.8%), mobility (36.7%) and anxiety (28.6%). Interventions targeted at clinical coronary artery disease (ie, angina reduction or management of post-MI heart failure) may fail to address these issues. The EQ-5D also allows for comparison with the health status of the general population and patients with other health conditions. The QOL deficit associated with MI is significant and persistent for many patients. However, the study is limited by lack of disease-specific symptom information. The most commonly-reported problem at 12 months was pain (41.8%), but it unclear if this is angina that may be prevented or treated with antianginal medication or revascularisation. It is also unknown how cardiovascular symptoms may contribute to impairments in activities and mobility. In addition, the study lacks detailed information about coronary artery disease burden and treatment. While revascularisation and referral to cardiac rehabilitation were more common among patients with improving QOL, we are left to speculate which, if any, of our standard MI treatments may improve overall health status. Finally, QOL may be influenced by unmeasured factors such as frailty, socioeconomic status, social support and depression. Additional research is needed to determine optimal targets for impacting QOL.

There are significant barriers to the use of PROs measures for the evaluation of cardiovascular patients. A gestalt clinical assessment of symptom burden and QOL is inadequate,7 but QOL surveys require time and engagement from patients and staff. Long-term lack of follow-up may be significant, as highlighted by only a 62.7% response rate for this study at 12 months. However, PROs are increasingly used for other conditions, and standardisation and improvements in technology may facilitate better integration into patients’ lives and routine clinical care.8 Even if PROs were consistently available, few treatments have been proven in clinical trials to impact QOL. One prominent exception is cardiac rehabilitation, which includes a comprehensive programme of exercise training, health counselling and monitoring by health professionals. Cardiac rehabilitation participation has been consistently associated with improvements in clinical outcomes and QOL.9 Despite this evidence and high rates of referral at discharge, cardiac rehabilitation remains underused.

The study by Munyombwe and colleagues argues for expanding the MI armamentarium to routinely include assessment of patient-reported symptoms and QOL. This will require consideration of PROs in clinical trials, registries, quality improvement interventions and routine care. While avoiding mortality and ischaemic events remains paramount, a greater focus on PROs can place QOL next to quantity of life as dual goals of MI treatment.