An American team did a retrospective cohort study from January 1, 1991, to December 31, 2014 which enrolled 122,077 patients at a tertiary care academic medical center, with a median follow-up of 8.4 years. The aim was to assess the association of all-cause mortality and cardiorespiratory fitness in patients undergoing exercise treadmill testing.
Death occurred in 13.,637 patients during 1,1 million person-years of observation. Risk-adjusted all-cause mortality was inversely proportional to cardiorespiratory fitness and was lowest in elite performers. The increase in all-cause mortality associated with reduced cardiorespiratory fitness was comparable to or greater than traditional clinical risk factors. In subgroup analysis, the benefit of elite over high performance was present in patients 70 years or older and patients with hypertension. Extreme cardiorespiratory fitness was associated with the lowest risk-adjusted all-cause mortality compared with all other performance groups.