RESUMEN
BACKGROUND: A slow heart rate recovery (HRR) after an exercise test is associated with an increased risk of all-cause mortality in asymptomatic individuals, but the data regarding additional prognostic information provided by HRR beyond other exercise test variables are inconsistent. We investigated the prognostic significance of HRR for premature death, particularly in relation to other exercise test variables. METHODS: The study subjects were a representative population-based sample of 1102 men (42-61 years of age) without cardiovascular disease, cancer or diabetes. HRR was defined as the difference between maximal HR and HR 2 min after a maximal symptom-limited exercise test using a cycle ergometer. The association between HRR and premature mortality was examined with Cox regression models. RESULTS: During an average follow-up of 18 years, 238 deaths occurred. HRR was an independent predictor of death [for a decrease of 12 beats min(-1) , relative risk (RR) 1.16, 95% CI 1.02-1.33, P = 0.02] after adjustment for age and established risk factors. When added in a Cox model with chronotropic response (decrease of 12 beats min(-1) , RR 1.09, 95% CI 0.93-1.27, P = 0.26) or cardiorespiratory fitness (decrease of 12 beats min(-1) , RR 1.12, 95% CI 0.98-1.30, P = 0.08), the association between a slow HRR and an increased risk of death was clearly weaker. CONCLUSION: A slow 2-min HRR after a cycle ergometer exercise test was an independent predictor of death in healthy middle-aged men after accounting for demographic and clinical characteristics. However, it was no longer predictive after accounting for chronotropic response and exercise capacity.
Asunto(s)
Enfermedades Cardiovasculares/mortalidad , Prueba de Esfuerzo/métodos , Tolerancia al Ejercicio/fisiología , Ejercicio Físico/fisiología , Frecuencia Cardíaca/fisiología , Mortalidad Prematura , Adulto , Causas de Muerte , Estudios de Cohortes , Prueba de Esfuerzo/normas , Finlandia , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas , Modelos de Riesgos ProporcionalesRESUMEN
OBJECTIVE: To investigate whether a workload which an individual is able to perform at the heart rate (HR) of 100 beats/min (WL(100)) independently predicts mortality in middle-aged men with known or suspected coronary heart disease (CHD). DESIGN: Prospective population-based study based on 365 middle-aged men with known or suspected CHD at baseline. RESULTS: During an average follow-up of 11.1 years, there were 75 deaths (20.5%). In Cox multivariable models mortality increased by 72% (95% CI 32% to 122%, p<0.001) with 1 SD (34 Watts) decrement in WL(100) after adjustment for age, examination year, alcohol consumption, body mass index, cigarette smoking, cardiac insufficiency, history of myocardial infarction, diabetes, myocardial ischaemia during exercise test, serum low-density lipoprotein and high-density lipoprotein cholesterol, systolic and diastolic blood pressure at rest, testing protocol, and use of HR-lowering medication. The risk of death was 2.4 (95% CI 1.5 to 4.0, p<0.001) times higher in 130 men with WL(100) <55 W than in 235 men with WL(100) >or=55 W. In men using and not using HR-lowering medication the risk of death increased 72% (95% CI 14% to 163%, p = 0.01), and 54% (95% CI 14% to 108%, p = 0.005) with 1 SD decrement in WL(100), respectively. WL(100 )improved the predictive power of the adjusted Cox models including other HR and exercise test variables. CONCLUSIONS: WL(100) predicts mortality in men with known or suspected CHD. The association of WL(100) with mortality was not explained by other well-established HR and exercise test variables. WL(100) is derived from a submaximal test which avoids the cardiovascular risks associated with a high-intensity exertion.