Clinical and prognostic association of total atrial conduction time in patients with heart failure: a report from Studies Investigating Co-morbidities Aggravating Heart Failure

BACKGROUND: The total atrial conduction time can be measured as the time from the onset of the P wave on the ECG to the peak of the A wave recorded at the mitral annulus using tissue Doppler imaging (A'; P-A'TDI); when prolonged, it might predict incident atrial fibrillation. METHODS: We measured P-A'TDI in outpatients with heart failure and sinus rhythm enrolled in the SICA-HF programme. RESULTS: P-A'TDI measured at the lateral mitral annulus was longer in patients with HF with reduced [LVEF<50%, N = 141; 126 (112-146) ms; P = 0.005] or preserved left ventricular ejection fraction [LVEF>50% and NT-proBNP > 125 ng/l, N = 71; 128 (108-145) ms; P = 0.026] compared to controls [N = 117; 120 (106-135) ms]. Increasing age, left atrial volume and PR interval were independently associated with prolonged P-A'TDI. During a median follow-up of 1251 (956-1602) days, 73 patients with heart failure died (N = 42) or developed atrial fibrillation (N = 31). In univariable analysis, P-A'TDI was associated with an increased risk of the composite outcome of death or atrial fibrillation, but only increasing log [NT-proBNP], age and more severe symptoms (NYHA III vs. I/II) were independently related to this outcome. Patients in whom both P-A'TDI and left atrial volume were above the median (127 ms and 64 ml, respectively) had the highest incidence of atrial fibrillation (hazard ratio 6.61, 95% CI 2.27-19.31; P < 0.001 compared with those with both P-A'TDI and LA volume below the median). CONCLUSION: Measuring P-A'TDI interval identifies patients with chronic heart failure at higher risk of dying or developing atrial fibrillation during follow-up.