The compelling article by Sinnadurai et al1 provides a snapshot of cardiac rehabilitation (CR) utilization and outcomes in a fairly representative, “real-world” sample across 4 regions in Poland, as part of the EUROASPIRE V (European Action on Secondary and Primary Prevention by Intervention to Reduce Events) initiative. While generalizability details were not provided, ultimately over 1000 patients from 14 centers were followed from cardiac hospitalization, undergoing an interview between 6 to 18 months after discharge. Strengths of this work include the cohort, use of valid and reliable measures, the length of follow-up, and the statistical approach using propensity score matching of patients who self-reported participating in CR versus those who did not. This work is also novel in several ways, particularly in terms of characterizing outcomes of residential CR programs.

The authors point to the disconcertingly low rates of CR referral at around 35%, which is lower than that in Europe more broadly (although patient enrolment rates were much higher as discussed below, which is encouraging).2 They raise several potential explanations, in line with reviews on physician factors related to CR referral practices,3 and also point to issues of CR capacity. Indeed, in the International Council of Cardiovascular Prevention and Rehabilitation (ICCPR)’s global audit of the same year (2016/2017),4 working with our partners in Poland, we ascertained there were approximately 56 programs in the country, each with a median annual capacity of 375 patients; thus, given the incidence of ischemic heart disease that year as reported in the Global Burden of Disease study, Poland requires over 210 000 more CR “spots” to treat them annually, such that there is only 1 “spot” for every 11 patients with ischemic heart disease in need (not considering heart failure, etc). Referral disparities, again commonly seen around the world, were also observed, although encouragingly, the persistent sex differences were not.5 This includes geographic variation, which may again be due to the differences in the capacity of the CR program in the country.6 There are proven interventions to increase referral and reduce these biases, such as systematic referral or exploiting electronic records.7 Clearly, these interventions can only be implemented where there is CR capacity to serve referred patients.

Again, as outlined above, the completion rate in those referred was 76%. This is unsurpassed in population-level data on the CR use to my knowledge, and higher than even average enrolment rates observed in other countries.8 As raised by the authors, this is likely due to the fact that CR care is reimbursed by government.9 It is also likely due to the residential nature of CR, unique in Eastern Europe.10 As with referral, the persistent sex differences in utilization were not observed,11 and overall, there were fewer disparities in utilization than are reported in the literature.12

Finally, with regard to outcomes, the sample size is somewhat low given the low referral rates, so the results must be considered within this context of low power. Clearly, the benefits of CR in Poland on so-called “hard outcomes” are well established.13 Benefits for quality of life are robust.14 Although caution is warranted due to potential self-report bias, the benefit with regard to tobacco cessation should be applauded. This is not commonly observed, and in fact in, other jurisdictions, smokers are often less well represented in CR (whereas they were significantly more likely to be referred in this cohort) and dropout. Many CR programs are insufficiently comprehensive to offer a robust tobacco cessation intervention,15 so clearly these programs are. Likely, the residential nature of the programs, delivered shortly after an acute event when motivation is high, also supports behavior change. Similarly, the effects of residential CR on blood glucose levels could be due to the intensive exposure to heart-healthy ways of eating.

There were no effects of CR on blood pressure or lipids; however, this is likely due to the fact that these were fairly well controlled before CR, and that medication use was high in those not attending CR as well. The lack of effect on body mass index is not unexpected, as this is often not changed with CR; patients often gain muscle but lose “waist”; waist circumference data may have revealed benefit in favor of CR. However, lack of association of CR completion with depression or anxiety symptoms, and physical activity was surprising (although there was a favorable trend for the latter). The authors point to the short duration of residential programs, and the time from program completion to follow-up to explain this. Indeed, residential programs are inherently of shorter duration than outpatient programs. The authors suggest that there is will to develop home-based CR in the country, as indeed ICCPR’s global audit identified none in the country.16 Indeed, an ICCPR member association, the Working Group on CR and Exercise Physiology of the Polish Cardiac Society, may wish to advocate for some form of home-based maintenance programming after the residential stay. This could support patients to incorporate their heart-healthy lifestyle changes into daily life in their community. Unfortunately, home-based CR is not reimbursed at this time,15 raising feasibility issues without advocacy.17

In conclusion, the authors should be congratulated for calling attention to CR use rates in Poland, the lack of CR capacity, and identifying the potential benefits of residential CR for both program engagement and patient outcomes, notably tobacco cessation and blood glucose control. Directions for future research stemming from this work include testing: whether enrolment, adherence, and completion are indeed greater where residential CR can be offered; whether tobacco users and patients with diabetes may be better served in these types of models; and whether CR reimbursement is associated with fewer utilization disparities than where the patient pays for all or part of CR care out of pocket. Policy implications of this work include augmenting CR capacity, which may involve advocating for stand-alone home-based services. Offering home-based programs as an adjunct following residential services to promote CR maintenance should also be explored to ensure the well-established benefits of CR are reaped.