Updates 19 July 2016
Drug Escalation vs Ablation for Recurrent VT.
Recurrent ventricular tachycardia among survivors of myocardial infarction with an implantable cardioverter–defibrillator (ICD) is frequent despite antiarrhythmic drug therapy. Two previous studies have shown that catheter ablation can reduce the recurrence of VT in these patients, but the benefit compared to escalated drug therapy has not yet been defined. Further evidence is presented in a study published in the July 14 issue of the New England Journal of Medicine.
In this randomized, controlled trial involving patients with ischemic cardiomyopathy and an ICD who had ventricular tachycardia despite the use of antiarrhythmic drugs, patients were assigned to receive either catheter ablation (ablation group) with continuation of baseline antiarrhythmic medications or escalated antiarrhythmic drug therapy (escalated-therapy group). In the escalated-therapy group, amiodarone was initiated if another agent had been used previously. The dose of amiodarone was increased if it had been less than 300 mg per day or mexiletine was added if the dose was already at least 300 mg per day. The primary outcome was a composite of death, three or more documented episodes of VT within 24 hours (VT storm), or appropriate ICD shock.
Of the 259 patients who were enrolled, 132 were assigned to the ablation group and 127 to the escalated-therapy group. During a mean (±SD) of 27.9±17.1 months of follow-up, the primary outcome occurred in 59.1% of patients in the ablation group and 68.5% of those in the escalated-therapy group (hazard ratio in the ablation group, 0.72; 95% confidence interval, 0.53 to 0.98; P=0.04). There was no significant between-group difference in mortality.
The authors concluded that in patients with ischemic cardiomyopathy and an ICD who had VT despite antiarrhythmic drug therapy, there was a significantly lower rate of the composite primary outcome of death, VT storm, or appropriate ICD shock among patients undergoing catheter ablation than among those receiving an escalation in antiarrhythmic drug therapy. In addition, treatment-attributed adverse events were more frequent in the escalated-therapy group than in the ablation group
Influence of Sacubitril/Valsartan on 30-Day Readmission after Heart Failure Hospitalization
Patients with heart failure are at high risk of readmission with the following months and 30 day readmission rates are increasingly used as a metric of care by health authorities and funders.
In the PARADIGM-HF study, a randomized trial comparing enalapril with the ARNI combination of sacubitril and valsartan in patients with LV ejection fraction < 35%, those receiving ARNI had a 20% reduction in the composite endpoint of cardiovascular death or heart failure hospitalization.
A substudy, published in the July 19th issue of JACC, reports that patients treated with ARNI had a 17.8% all-cause readmission rate at 30 days compared to 21.0% for the enlapril-treated patients (OR 0.74, CI = 0.56 – 0.97, p=0.031). Rates of readmission for heart failure were also less for those receiving ARNI (9.7%) than for those receiving enalapril (13.4%, OR = 0.62, CI = 0.45 – 0.87, p=0.006).
The authors caution that this was not a pre-specified analysis of the PARADIGM-HF study, but did note that there were no differences in baseline characteristics or severity of heart failure between the ARNI and enalapril groups. The authors conclude that the ARNI combination provides additional benefit in reducing risk of 30 day readmission for patients with chronic, symptomatic heart failure and reduced ejection fraction.
Migraine and Patent Foramen Ovale
Several studies have reported an association between patent foramen ovale and migraine and, given the debilitating effect of migraine, intervention upon the PFO has been an interesting treatment target. Two previous studies have not been able to demonstrate benefit from PFO closure. The PRIMA trial was commenced in 2006 and sought to determine whether or not PFO closure was beneficial in reducing or preventing migraine.
The study was designed to recruit 60 patients per arm, however recruitment was slow and the sponsor terminated the study in 2012. Study results are reported for 40 patient randomized to PFO closure and 43 randomized to medical management, who completed 12 months follow-up.
The primary endpoint (reduction in monthly migraine days at 1 year after randomization) was not reached according to the intention-to-treat analysis. The mean reduction of migraine days per month was 1.2 days greater in the PFO closure group when compared
with the control group, but this was not significant (22.9 vs. 21.7 days; P = 0.17). Migraine medication use was similar in both groups.
Post hoc analyses showed some intriguing results: PFO closure was associated with a greater mean reduction in migraine with aura days per month (22.4 vs. 20.6 days; P = 0.0141) and fewer migraine attacks with aura compared with the control group (22.0 vs. 20.5; P = 0.0003; Table 4, Figure 3A). In addition, 4 of 40 patients (10%) in the PFO closure group were free of migraine attacks during months 10–12 compared with none among 41 controls (P = 0.055).
There were 6 adverse events in the PFO closure group, however all resolved without sequelae.
The authors concluded that PFO device closure with the Amplatzer Occluder was safe in the long term, however the primary endpoint to reduce migraine days at 1 year after randomization was not achieved. Although post hoc analyses raise the interesting hypothesis that PFO closure might decrease migraine attacks with aura in patients with predominantly migraine with aura attacks at baseline, this would require yet further clinical trial study.