Abnormal Circadian Blood Pressure Profile as a Prognostic Marker in Patients with Nonischemic Dilated Cardiomyopathy

Objectives: An abnormal circadian blood pressure (BP) profile is considered a risk factor for cardiovascular disease. However, its significance in heart failure patients with nonischemic etiology is unknown. Herein, we investigated the prognostic value of a circadian BP profile in patients with nonischemic dilated cardiomyopathy (NIDCM). Methods: We enrolled 114 NIDCM patients (76 males, mean age 53.1 years). The percent nighttime BP fall (%NBPF) was defined using ambulatory BP monitoring as a percent decrease in mean systolic BP in nighttime from daytime. All patients were divided into three groups: dipper (%NBPF ≥10), non-dipper (0 ≤ %NBPF < 10), and riser (%NBPF <0). Results: Riser patients had the highest serum creatinine levels (dipper, 0.78 ± 0.20 mg/dl; non-dipper, 0.85 ± 0.21 mg/dl; riser, 0.99 ± 0.23 mg/dl; p = 0.006). In survival analysis, riser patients had the highest cumulative cardiac-related deaths (log-rank, p = 0.001), which was an independent predictor of cardiac-related deaths (hazard ratio, 12.6; 95% confidence interval, 1.76-253; p = 0.01). Multivariate analysis revealed that the norepinephrine level at 24-hour collected urine (24 h U-NE) and the serum creatinine level were independent determinants of %NBPF (adjusted R² = 0.20; 24 h U-NE, p = 0.0001; serum creatinine, p = 0.04). Conclusions: The riser profile was associated with poor prognosis of NIDCM, which may reflect impaired sympathetic nervous system activity. Evaluating the circadian BP profile may be useful for risk stratification in NIDCM patients.