Prevention of recurrent sudden cardiac arrest: role of provocative electropharmacologic testing

This study evaluates the usefulness of serial provocative electropharmacologic testing for predicting the efficacy of prophylactic antiarrhythmic treatment regimens in patients resuscitated from sudden cardiac arrest in the absence of acute myocardial infarction. Testing was carried out in 34 consecutive patients (28 men and 6 women) who required cardiopulmonary resuscitation and direct current countershock for treatment of primary ventricular fibrillation (28 patients), ventricular tachycardia (5 patients) or excessively rapid heart rate during atrial fibrillation with preexcitation (1 patient).In 8 (24%) of the 34 patients, drug testing either was not feasible because of absence of inducible arrhythmia or was incomplete because of patient withdrawal from study; and 3 of these 8 patients had recurrent sudden cardiac arrest within 10 to 19 months. In an additional five patients, treatment regimens failed to prevent initiation of sustained ventricular tachyarrhythmias in the catheterization laboratory, and two of these five patients had cardiac arrest recurrences within 2 weeks to 25 months of follow-up. In the remaining 21 (62%) of the 34 patients, including 3 patients with preexcitation syndrome, a drug regimen or surgical treatment, or both, was found that prevented inducible life-threatening tachyarrhythmias in the laboratory. Subsequently, only 1 (5%) of these 21 patients died suddenly within a 7 to 38 month (mean ± standard deviation, 18 ± 8.3) follow-up period. Thus, provocative electropharmacologic testing appears to be useful in predicting response to therapy in survivors of sudden cardiac arrest

Effect of Chronic Digoxin Use on Mortality and Heart Failure Hospitalization in Pulmonary Arterial Hypertension

Background Digoxin acutely increases cardiac output in patients with pulmonary arterial hypertension (PAH) and right ventricular failure; however, the effects of chronic digoxin use in PAH are unclear. Methods and Results Data from the Minnesota Pulmonary Hypertension Repository were used. The primary analysis used likelihood of digoxin prescription. The primary end point was a composite of all‐cause mortality or heart failure (HF) hospitalization. Secondary end points included all‐cause mortality, HF hospitalization, and transplant‐free survival. Multivariable Cox proportional hazards analyses determined the hazard ratios (HR) and 95% CIs for the primary and secondary end points. Among 205 patients with PAH in the repository, 32.7% (n=67) were on digoxin. Digoxin was more often prescribed to patients with severe PAH and right ventricular failure. After propensity score‐matching, 49 patients were digoxin users, and 70 patients were nonusers; of these 31 (63.3%) in the digoxin group and 41 (58.6%) in nondigoxin group met the primary end point during a median follow‐up time of 2.1 (0.6–5.0) years. Digoxin users had a higher combined all‐cause mortality or HF hospitalization (HR, 1.82 [95% CI, 1.11–2.99]), all‐cause mortality (HR, 1.92 [95% CI, 1.06–3.49]), HF hospitalization (HR, 1.89 [95% CI, 1.07–3.35]), and worse transplant‐free survival (HR, 2.00 [95% CI, 1.12–3.58]) even after adjusting for patient characteristics and severity of PAH and right ventricular failure. Conclusions In this retrospective, nonrandomized cohort, digoxin treatment was associated with greater all‐cause mortality and HF hospitalization, even after multivariate correction. Future randomized controlled trials should assess the safety and efficacy of chronic digoxin use in PAH