Influence of Prevalent and Incident Atrial Fibrillation on Post-Trial Major Events in ALLHAT

Cardiovascular Events after New-Onset Atrial Fibrillation in Adults with CKD: Results from the Chronic Renal Insufficiency Cohort (CRIC) Study

BACKGROUND

Atrial fibrillation (AF), the most common sustained arrhythmia in CKD, is associated with poor clinical outcomes in both patients without CKD and patients with dialysis-treated ESRD. However, less is known about AF-associated outcomes in patients with CKD who do not require dialysis.

METHODS

To prospectively examine the association of new-onset AF with subsequent risks of cardiovascular disease events and death among adults with CKD, we studied participants enrolled in the Chronic Renal Insufficiency Cohort Study who did not have AF at baseline. Outcomes included heart failure, myocardial infarction, stroke, and death occurring after diagnosis of AF. We used Cox regression models and marginal structural models to examine the association of incident AF with subsequent risk of cardiovascular disease events and death, adjusting for patient characteristics, laboratory values, and medication use.

RESULTS

Among 3080 participants, 323 (10.5%) developed incident AF during a mean 6.1 years of follow-up. Compared with participants who did not develop AF, those who did had higher adjusted rates of heart failure (hazard ratio [HR], 5.17; 95% confidence interval [95% CI], 3.89 to 6.87), myocardial infarction (HR, 3.64; 95% CI, 2.50 to 5.31), stroke (HR, 2.66; 95% CI, 1.50 to 4.74), and death (HR, 3.30; 95% CI, 2.65 to 4.12). These associations remained robust with additional adjustment for biomarkers of inflammation, cardiac stress, and mineral metabolism; left ventricular mass; ejection fraction; and left atrial diameter.

CONCLUSIONS

Incident AF is independently associated with two- to five-fold increased rates of developing subsequent heart failure, myocardial infarction, stroke, or death in adults with CKD. These findings have important implications for cardiovascular risk reduction.

Risk Factors Influencing Outcomes of Atrial Fibrillation in ALLHAT

BACKGROUND AND AIMS

ALLHAT, a randomized, double-blind, active-controlled, multicenter clinical trial of high risk hypertensive participants, compared treatment with an ACE-inhibitor (lisinopril) or calcium channel blocker (amlodipine) with a diuretic (chlorthalidone). Primary outcome was the occurrence of fatal coronary heart disease or nonfatal myocardial infarction. For this report, post-hoc analyses were conducted to determine the contribution of baseline characteristics of participants with or without baseline or incident atrial fibrillation (AF) and atrial flutter (AFL) to stroke, heart failure (HF), coronary heart disease (CHD), and mortality outcomes.

METHODS AND RESULTS

Minnesota Coding of baseline and biennial in-trial ECGs was used to determine the 334 baseline and 537 incident AF/AFL cases, respectively participants with AF/AFL: Cox regression was used to estimate hazard ratios of presence versus absence of either baseline or incident AF/AFL (as time-dependent covariate) for occurrence of stroke, CHD, HF, or mortality, while adjusting for selected baseline characteristics. Adjusted Cox regression was used to obtain hazard ratios (HRs) for presence versus absence of selected baseline characteristics among those with and without either baseline or incident AF/AFL. After adjusting for baseline characteristics, baseline AF/AFL was associated with stroke, HF, and mortality (HRs [95% CIs] 3.18, [2.34-4.33]; 2.65 [2.02-3.49]; and 2.10 [CI, 1.73-2.55], respectively, P < 0.05). Incident AF/AFL was a significant risk factor for HF and mortality (HRs 2.80 and 2.06, respectively, P < 0.05). Risk factor profiles for clinical outcomes for those with and without baseline or incident AF/AFL were largely similar.

CONCLUSIONS

AF/AFL is a significant risk factor for stroke, HF, and mortality. Additional risk factors for these outcomes were generally similar for participants with and without baseline or incident AF/AFL.