Cardiorespiratory fitness and the incidence of coronary surgery and postoperative mortality: the HUNT study

Abstract

OBJECTIVES Low physical activity and cardiorespiratory fitness are known risk factors for coronary artery disease, but how they affect the risk of undergoing coronary artery bypass graft surgery is not established. We explored how physical activity and estimated cardiorespiratory fitness affect the risk of coronary surgery and postoperative outcome. METHODS Participants with no history of coronary disease from the second wave of the Trøndelag Health Study (HUNT2) were cross-linked with the local heart surgery register and the Norwegian Cause of Death Registry. Cardiorespiratory fitness was estimated by a previously developed algorithm using clinical and self-reported information. Fine-Gray competing risk analyses were used to calculate the risk of undergoing isolated coronary surgery across physical activity groups and estimated cardiorespiratory fitness (mL/kg/min) as quintiles and per 1 metabolic equivalent of task (MET) (3.5 mL/kg/min). RESULTS We included 45,491 participants. The mean population age was 46.0 [standard deviation (SD) 15.8] years, and the mean estimated fitness was 41.3 (SD 8.9) mL/kg/min. A total of 672 (1.5%) participants underwent coronary surgery during the follow-up period. The risk of undergoing isolated coronary surgery was 26% [95% confidence interval (CI) 3–44] lower for those classified as highly active compared to those classified as least active. Further, an 11% (95% CI 6–15) lower risk per 1-MET (3.5 mL/kg/min) of higher fitness. Finally, we observed a 15% (95% CI 5–23) lower mortality risk after surgery per 1-MET of higher fitness among those undergoing surgery. CONCLUSIONS High levels of physical activity and high estimated fitness levels were inversely associated with the risk of developing coronary disease requiring surgery and overall mortality after surgery.

Long-Term Mortality Risk According to Cardiorespiratory Fitness in Patients Undergoing Coronary Artery Bypass Graft Surgery

“…Recently, Smenes and the other investigators in the HUNT study demonstrated an inverse and graded relationship between physical activity and survival after CABG similar to our own findings, noting a mortality improvement of 15% for each 1-MET increase in estimated CRF [19]. An important distinction between this study and our own is the manner in which CRF was determined.…”

“…A study using the STS database found a significant association between low fitness and 30-day mortality after CABG; however, the association between CRF and long-term outcomes after CABG has not been adequately studied [18]. To date, the only study to investigate the relationship between CRF and survival after CABG relied on patient reports of physical activity to estimate fitness levels and did not include direct objective measures of CRF such as treadmill exercise tolerance testing [19].…”

Effects of sevoflurane on left ventricular function by speckle-tracking echocardiography in coronary bypass patients: A randomized trial

“…Coronary artery bypass grafting (CABG) presents a potent revascularization advantage in patients with multivessel coronary artery disease (CAD) [ 1 – 4 ] . However, the complexity of CABG can lead to various perioperative complications, increasing the risk of postoperative readmissions and mortality [ 5 ] . Optimal intraoperative management can reduce perioperative complications and improve the prognosis of such patients [ 6 ] .…”