Sudden Cardiac Death in Hypertensive Patients

Abstract

In patients with hypertension, but without established cardiovascular disease, predictive factors for sudden cardiac death (SCD) remain undefined. We followed for an average of 10.3 years a cohort of 3242 initially untreated hypertensive patients without evidence of coronary or cerebrovascular heart disease at entry. All patients underwent a complete clinical examination which included ECG and 24-hour ambulatory blood pressure monitoring. At entry, the mean age of patients was 50.0 years, 45% were women, and 6.1% had type 2 diabetes mellitus. Average office blood pressure was 154/96 mm Hg, and average 24-hour ambulatory blood pressure was 136/86 mm Hg. Prevalence of left ventricular hypertrophy at ECG was 13.9%. During follow-up, SCD occurred in 33 patients at a rate of 0.10 per 100 patient-years (95% CI, 0.07-0.14). The rate of SCD was 0.07 and 0.30 per 100 patient-years, respectively, in the cohort of patients without and with ECG left ventricular hypertrophy ( P<0.01). In a multivariable Cox model with Firth penalized maximum bias reduction method for rare outcome events, left ventricular hypertrophy almost tripled the risk of SCD (adjusted hazard ratio, 2.99; 95% CI, 1.47-6.09; P=0.002) after adjustment for age ( P<0.0001), sex ( P=0.019), diabetes mellitus ( P<0.0001), and 24-hour ambulatory pulse pressure ( P=0.036). For each 10 mm Hg increase in 24-hour ambulatory pulse pressure, the risk of SCD increased by 35%. The time-dependent area under the receiver operating characteristic curve was 0.85 (95% CI, 0.74-0.96). We conclude that in patients with hypertension without established cardiovascular disease, age, diabetes mellitus, ECG left ventricular hypertrophy, and 24-hour ambulatory pulse pressure are independent prognostic markers for SCD in the long-term.