Effect modification of aortic atheroma on the prognostic value of heart rate in hypertension

Although some epidemiological studies have advocated a prognostic value of heart rate (HR) in hypertensive patients, the influence of vascular damages on this prognostic value has not been tested yet.

HRs were collected by pulse palpation in 1204 primary hypertensive patients in sinus rhythm without cardiac-slowing drugs. Aortic damages were assessed by aortography, whereas cardiac disease was assessed by medical history, symptoms and electrocardiogram.

In a multivariable Cox model adjusted for major confounders, HR was of prognostic significance for all-cause [hazard ratio 1.12 (1.06-1.19) for 10 bpm increment and 1.39 (1.18-1.64) for HR ≥82 vs. <82 bpm] and cardiovascular death [hazard ratio 1.10 (1.02-1.20) for 10 bpm increment and 1.37 (1.09-1.72) for HR ≥82 vs. <82 bpm] after 35 years of follow-up. This association was particularly manifested at 15 years of follow-up. At that time, with the same multivariable survival model, the association between HR and cardiovascular death was stronger in patients with aortic atheroma [2.76 (1.47-5.18) for an HR ≥82 vs. <82 bpm] than in patients without [hazard ratio 1.36 (0.76-2.43) for an HR ≥82 vs. <82 bpm, P for interaction = 0.054]. Similarly, the association between HR and cardiovascular death was stronger in patients with an overt cardiac disease than those without (P for interaction = 0.044).

In hypertensive patients, the prognostic significance of HR for cardiovascular outcome is modulated by the presence of aortic atherosclerosis or cardiac disease. This should prompt us to a thorough examination of cardiovascular damages in hypertensive patients when HR is elevated.