Background:
Chronic obstructive pulmonary disease (COPD) is associated with an increased risk of cardiovascular (CV) disease and CV mortality. A recent large, population-based study suggested that COPD is associated with an increased risk of sudden cardiac death (SCD). However, whether COPD predicts SCD in hypertensive patients during aggressive blood pressure (BP) lowering has not been examined.
Methods:
Risk of SCD was examined in relation to a history of COPD in 9193 hypertensive patients with ECG left ventricular hypertrophy (LVH) who were randomly assigned to losartan- or atenolol-based treatment. A history of COPD was present in 385 patients (4.2%). SCD, a prespecified secondary endpoint in LIFE, was defined as death that was sudden and unexpected, including observed arrhythmic deaths and those not attributable to myocardial infarction (MI), intractable heart failure (HF) or other identifiable cause, occurring within 24 hours of symptom onset or when the subject was last seen alive if unwitnessed SCD.
Results:
During mean follow-up of 4.8±0.9 years, 178 patients (2.4%) had SCD, with a higher incidence rate per 1000 person-years in those with COPD: 9.0; 95% CI, 6.1-11.9 vs 3.8; 95% CI, 3.4-4.2; p=0.001. In a univariate Cox model, COPD was associated with a > 2-fold increased risk of SCD (HR 2.36, 95% CI 1.42-3.95, p=0.001). In a multivariable Cox regression model that adjusted for other predictors of SCD in this population (randomized treatment, age, gender, race, history of atrial fibrillation, stroke or transient ischemic attack, baseline serum creatinine and glucose entered as standard covariates and incident MI, incident HF and in-treatment diastolic pressure, heart rate, QRS duration, HDL cholesterol, and use of hydrochlorothiazide or a statin entered as time-varying covariates), COPD remained associated with a nearly 2-fold increased risk of SCD (HR, 1.82; 95% CI, 1.04-3.18, p=0.035).
Conclusions:
COPD is associated with an increased risk of SCD in hypertensive patients. The higher SCD risk in COPD patients persists after adjusting for the higher prevalence of risk factors in COPD patients, in-treatment blood pressure, incident MI and HF, and the established predictive value of in-treatment ECG LVH and heart rate for SCD in this population.
High-intensity versus low-intensity noninvasive positive pressure ventilation in patients with acute exacerbation of chronic obstructive pulmonary disease (HAPPEN): study protocol for a multicenter randomized controlled trial
