Systolic Blood Pressure and Risk for Ventricular Arrhythmia in Patients with an Implantable Cardioverter Defibrillator.
Low systolic blood pressure (SBP) was previously suggested to be a marker for heart failure and mortality in patients with low left ventricular (LV) ejection fraction (EF). We aimed to explore the association of SBP on risk of ventricular tachyarrhythmias (VTA) and atrial arrhythmias as well as appropriate and inappropriate ICD therapy. The study population comprised 1481/1500 (99%) patients enrolled in the MADIT-RIT trial. Multivariate Cox proportional hazards regression modeling was used to identify the association of baseline SBP (recorded prior to ICD implantation) with the risk of VTA > 170 bpm during follow-up (primary endpoint) and atrial arrhythmia, appropriate and inappropriate ICD therapy, hospitalization and death (secondary endpoints). SBP was dichotomized at 120 mmHg (approximate mean and median) and was also assessed as a continuous measure. Multivariate analysis showed that each 10 mmHg decrement in SBP was associated with corresponding 11% increased risk for VTA (P=0.008). Low SBP (≤120 mmHg) was associated with a significant 58% (p=0.002) increased risk for VTA ≥170 bpm; 53% (p=0.019) increased risk for VTA ≥200 bpm; and 65% (p=0.001) increased risk for appropriate ICD therapy, as compared with SBP >120 mmHg. Low SBP was not associated with increased risk of atrial arrhythmias, and inappropriate ICD therapy. In conclusion, in MADIT-RIT, SBP (≤120 mmHg) predicted higher rates of VTA. These findings suggest that SBP may be utilized for VTA risk stratification in candidates for primary ICD therapy.