Impaired coronary artery vasodilation during skin surface cooling in healthy older adults

Abstract

Cardiovascular‐related mortality increases in the cold winter months, particularly in older adults. To determine whether coronary artery blood flow responses to skin surface cooling differ with age, we studied 9 young (25±1 yrs) and 10 older healthy adults (65±2 yrs). We hypothesized that left anterior descending coronary artery blood velocity (CBV) responses, measured using Doppler transthoracic echocardiography, to skin surface cooling (15–18° C water perfused suit for 20 min) would be impaired with age. We found that cooling increased left ventricular wall stress, a determinant of myocardial oxygen consumption, in young (185.6±6.5 to 202.9 ±10.4 mmHg, P < 0.05) and older adults (189.1±8.8 vs. 222.7±14.7 mmHg, P < 0.01) although the magnitude of this response was twofold greater in older adults (Δ9.13±3.48% vs. Δ17.62±3.24%, young and older, respectively; P=0.09). Despite increased left ventricular wall stress during cooling in young and older adults CBV increased only in the young (20.86±1.32 to 25.56±1.24 cm/s, p<0.01) and not older group (17.60±1.09 to 19.93 ±0.97 cm/s, p=0.11). These data suggest that an impaired coronary vasodilator response to cold stress may contribute to age‐dependent increases in cardiovascular‐related mortality during the winter months in healthy adults.Support: NIH HL92309, AG24420 and M01 RR10732