Background: Cardiac rehabilitation programs (CRP) are medically supervised exercise-based interventions for patients (pts) who experience a cardiac event. It has been recognized that CRP improved coronary heart disease (CHD) risk factors (RF) and functional capacity. Obesity is a major CHD RF. On the other hand, obese pts may have some difficulties in CRP performance. The aim of this study was to compare obese and non-obese pts regarding their baseline clinical profile and response to a CRP.

Methods: We analysed data from a prospectively collected registry of 433 consecutive pts who underwent CRP after an acute coronary syndrome (ACS) from January 2009 to October 2015. Pts were divided in two groups according to their body mass index (BMI): BMI ≥30kg/m² (obese) and BMI <30kg/m² (non-obese). Exercise performance was assessed using both duration and metabolic equivalents (METs) achieved in standard exercise test (ET) using Bruce protocol before and after CRP.

Results: Ninety-nine (22.9%) pts were obese. No differences concerning age (54.1±10.1 vs 54.7±9.6 years) or gender (79.8% vs. 86.7% males) were found between groups. Obese pts had a mean waist circumference 108.4±6.1 cm in males and 102.1±7.6 cm in females, while non-obese pts presented a mean waist circumference of 93.8±5.5 in men and 81.5±7.4 cm in women. Among CHD RF, hypertension and diabetes were more frequent in obese pts (64.6% vs. 40.1%, p<0.001 and 29.6% vs. 16.3%, p=0.003, respectively). Obese pts also showed higher levels of depression symptoms at admission (p=0.005). The index coronary event affected 1 coronary artery in more than half of pts in both groups. Echocardiography showed a slightly higher mean fractional ejection in obese compared to non-obese (55.5±10.8% vs 51.7±12.0%, p=0.012). Baseline functional capacity was lower in obese group both in duration (7.05±2.33 min vs 8.38±2.23 min; p<0.001) and intensity (7.67±2.32 METs vs 8.91±2.18 METs; p<0.001). Both groups significantly improved their functional capacity with obese pts showing higher relative improvement in both duration (+36.7% vs. 28.8%, p=0.043) and intensity (+32.4% vs. 25.9%, p=0.079).

Conclusion: Obesity is an epidemic in western countries. It is tightly linked to CHD. Overweight should be a main focus in both primary and secondary prevention. Response to exercise training exerts similar, if not higher, benefits in obese pts and this group should be priority in CRP.