PREvention of recurrent arrhythmias with Mediterranean diet (PREDIMAR) study in patients with atrial fibrillation: Rationale, design and methods.

Background: Atrial fibrillation (AF) is the most common cardiac arrhythmia. Catheter ablation aims to restore sinus rhythm. However, relapses occur in up to 30% of patients. A Mediterranean diet (MedDiet) enriched with extra-virgin olive oil (EVOO) substantially reduced the incidence of AF in the PREDIMED trial. The PREDIMAR will test a similar intervention in secondary prevention. Methods: PREDIMAR is a multicenter, randomized, single-blind trial testing the effect of a MedDiet enriched with EVOO to reduce tachyarrhythmia relapses after AF ablation. The primary outcome is the recurrence of any sustained atrial tachyarrhythmia after ablation (excluding those occurring only during the first 3 months after ablation). The target final sample size is 720 patients (360 per group) recruited from 4 Spanish hospitals. A remote intervention, maintained for 2 years, is delivered to the active intervention group including periodic phone calls by a dietitian and free provision of EVOO. The control group will receive delayed intervention after trial completion. Routine electrocardiogram (ECG) and Holter ECG are performed, and a portable cardiac rhythm monitoring device is provided to be worn by participants during 15 months. Results: Recruitment started in March 2017. Up to July 2019, 609 patients were randomized (average inclusion rate: 5.3 patients/wk). Retention rates after 18 months are >94%. Conclusions: If our hypothesis is confirmed, the utility of the MedDiet enriched with EVOO in slowing the progression of AF will be proven, preventing recurrences and potentially reducing complications.

[Dual-chamber pacemakers in obstructive hypertrophic cardiomyopathy: gradient variation with stress echocardiography]. / Marcapasos bicameral en la miocardiopatía hipertrófica obstructiva: variación del gradiente con ecocardiografía de estrés.

INTRODUCTION: Permanent cardiac pacing with a dual chamber pacemaker has become a valid alternative in treatment of patients with obstructive hypertrophic cardiomyopathy and refractory symptoms to pharmacological treatment, with a significant decrease of left ventricular outflow tract gradient. AIM: To assess any modification of the gradient with dobutamine stress echocardiography. PATIENTS AND METHODS: We study 10 patients with obstructive hypertrophic cardiomyopathy and angina and/or dyspnea refractory to customary pharmacological treatment. A dual chamber pacemaker had been implanted 3-6 months previously. A dobutamine stress echocardiography was performed, beginning with a 10 microgram/kg/min infusion, with increases of 10 micrograms each 3 minutes until a maximum of 40. Modification of subaortic gradient, severity of systolic anterior motion of mitral valve (SAM, degree 0-3/3) and severity of mitral regurgitation (degree 0-4/4) were assessed. RESULTS: Subaortic gradient decreased in all patients after pacemaker implantation (90 +/- 15 vs 20 +/- 10 mmHg; p < 0.001). With stress echocardiography the gradient increased in all patients (20 +/- 10 to 101 +/- 13 mmHg; p < 0.001). After implant there were only two patients with a +1 SAM, while during stress echocardiography SAM developed in all patients in +2 or +3 degree. Three patients had +1 mitral regurgitation after pacemaker implantation but during stress echocardiography 2-4/4 mitral regurgitation developed in all patients. CONCLUSIONS: Permanent dual chamber pacing decreased left ventricular outflow tract gradient in patients with obstructive hypertrophic cardiomyopathy, but during dobutamine stress echocardiography obstruction echocardiographic signs appeared.