Blood pressure and other determinants of new-onset atrial fibrillation in patients at high cardiovascular risk in the Ongoing Telmisartan Alone and in Combination With Ramipril Global Endpoint Trial/Telmisartan Randomized AssessmeNt Study in ACE iNtolerant subjects with cardiovascular Disease studies.

BACKGROUND: Evidence on new-onset atrial fibrillation in high-risk vascular patients without heart failure is limited. New-onset atrial fibrillation was a prespecified secondary objective of the Ongoing Telmisartan Alone and in Combination With Ramipril Global Endpoint Trial (ONTARGET)/Telmisartan Randomized AssessmeNt Study in ACE iNtolerant subjects with cardiovascular Disease (TRANSCEND) studies.

METHODS: We studied 30 424 ONTARGET/TRANSCEND patients (mean age ± SD, 66.4 ± 7.0) with vascular disease or complicated diabetes who were in sinus rhythm at entry. A copy of ECG was sent to central office every time new atrial fibrillation was detected by investigators.

RESULTS: During a median follow-up period of 4.7 years, new atrial fibrillation occurred in 2092 patients (15.1 per 1000  patient-years). Risk of atrial fibrillation increased with age, SBP and pulse pressure, left ventricular hypertrophy, BMI, serum creatinine and history of hypertension, coronary artery disease and cerebrovascular disease (all P < 0.01). After adjustment for BMI and other variables, atrial fibrillation risk increased with hip circumference. History of hypertension was associated with a 34% higher risk of new atrial fibrillation. New atrial fibrillation portended an increased risk of congestive heart failure [hazard ratio 2.89, 95% confidence interval (CI) 2.45-3.40, P < 0.01] and cardiovascular death (hazard ratio 1.22, 95% CI 1.05-1.41, P < 0.01). Risk of stroke was unaffected (hazard ratio 1.14, 95% CI 0.93-1.40), whereas that of myocardial infarction was reduced (hazard ratio 0.64, 95% CI 0.50-0.82). Patients with new atrial fibrillation were more likely to receive vitamin K antagonists (P < 0.01), statins (P < 0.05) and β-blockers (P < 0.01) than those in sinus rhythm.

CONCLUSION: New atrial fibrillation is common in high-risk vascular patients and is associated with several risk factors including history of hypertension. Hip circumference was the strongest anthropometric predictor. Despite extensive use of modern therapies, new atrial fibrillation carries a high risk of congestive heart failure and death over a relatively short term.