Prognostic role of education levels after cardiac surgery and inhospital cardiac rehabilitation

It is well known that in many industrialised countries cardiovascular disease mortality is higher among patients with lower socioeconomic status, as indicated by education level, occupational class or income level.1 Educational inequality is one of the most important socioeconomic factors contributing to cardiovascular risk and cardiovascular disease (CVD).2,3 Even though the major cardiovascular risk factors explain much of the association between education and CVD,4,–6 whether low education levels are to be considered as an independent cardiovascular risk factor is still an open issue and little evidence has been produced on the lifetime risks of CVD according to education level.7,,–10 On the other hand, no study has evaluated the prognostic role of education level in secondary cardiovascular prevention patients undergoing cardiac rehabilitation. Therefore, the aim of the present study was to evaluate the long-term prognostic role of education level after an inhospital exercise-based cardiac rehabilitation programme (CRP). We created a monocentric observational prospective registry including consecutive patients undergoing CRP at the cardiovascular prevention and rehabilitation unit of the Don Gnocchi Foundation, University of Parma, from January 2007 to May 2015. All patients underwent different types of intervention, including valve replacement, coronary artery bypass grafting (CABG) alone and combined valve and CABG. The patients completed a standard inhospital CRP, lasting approximately 2 weeks, consisting of supervised exercise sessions (120 minutes per day), comprehensive lifestyle and risk factor management through medical and psychological counselling and optimisation of medical therapy. Three levels of education have been defined: low (primary school), intermediate (secondary education) and high (university degree). Follow-up was achieved through a telephonic questionnaire performed by a physician after receiving oral informed consent by patients; endpoints were further confirmed analysing medical records. Primary endpoints were all-cause mortality and cardiovascular mortality, while secondary endpoints were combined major adverse cardiovascular/cerebrovascular events (MACCE) such as: cardiovascular death, acute coronary syndrome, stroke and heart failure. Kaplan–Meier analysis was used to create event-free survival curves between education levels. Cox proportional hazard regression analysis was performed to create event-free survival curves. Multivariate Cox regression analysis was used to create adjustment of hazard ratio (HR) for age, gender, arterial hypertension, diabetes and type of cardiac surgery. Significance was defined as a P value less than 0.05. All statistics were performed using SPSS version 23 (IBM Corporation). The study included 2042 patients with available education level and follow-up data. Risk of overall mortality, cardiovascular mortality and major adverse cardiovascular/cerebrovascular events (MACCE) according to education levels. Cox proportional hazard analysis showed an overall mortality, cardiovascular mortality and MACCE risk significantly lower in patients with high education levels (blue line). Risk of overall mortality, cardiovascular mortality and major adverse cardiovascular/cerebrovascular events (MACCE) according to education levels. Cox proportional hazard analysis showed an overall mortality, cardiovascular mortality and MACCE risk significantly lower in patients with high education levels (blue line). Our study has demonstrated that educational attainment represents an independent predictor of overall mortality, cardiovascular mortality and MACCE in patients undergoing CRP after myocardial revascularisation and/or cardiac valve surgery. In particular, a reduction of 47% in the relative risk of cardiovascular death as well as of 39% in overall mortality have been found in patients with high education levels. Moreover, although patients with low education levels were significantly older, with a higher rate of hypertension and diabetes, the prognostic value of educational attainment was confirmed even when adjusted for these confounding factors. To the best of our knowledge, our study represents the first investigation that demonstrates the prognostic role of educational attainment in patients undergoing CRP. In fact, only little evidence has been produced on the lifetime CVD risk according to education levels and was mainly conducted in a primary prevention setting.7,,–10 Even though the present study was not designed to investigate the mechanisms linking education levels and prognosis, the potential beneficial effects of high education levels in CRP patients could be: better awareness of disease status, better therapy adherence, better cooperation between physician and patients and better learning during medical, physiotherapeutic and nursing counselling. In conclusion, these results highlight the importance of education level evaluation during CRP. In particular, physicians should take care of patients with low educational attainment levels aiming to provide a more individualised approach of counselling, in terms of both the duration and quality of proposal (adequate to patients' comprehension level), and to offer closer follow-up monitoring.