麻豆传媒

BOSTON -- An olive oil-enhanced Mediterranean diet didn't help prevent atrial fibrillation (Afib, or AF) recurrence after ablation in the PREDIMAR randomized trial, although there was a signal for benefit in paroxysmal cases.

The 18-month cumulative incidence of tachyarrhythmia recurrence was similar for the intervention and a fairly Mediterranean usual diet in the Spanish population (HR 0.86, 95% CI 0.68-1.10), reported Maria Barrio-Lopez MD, PhD, of University Hospital HM Monteprincipe in Madrid, at the annual meeting.

However, a post hoc analysis looking only at the paroxysmal Afib cases did suggest a significant benefit of the diet intervention (HR 0.68, 95% CI 0.48-0.97).

"Although it's very impressive -- I mean, it almost looks like these people got a second ablation -- these are post hoc subanalyses, and so they have to be considered hypothesis-generating," commented HRS session study discussant Christine Albert, MD, MPH, of Cedars-Sinai Medical Center in Los Angeles. And, she added, "although those subgroup analyses are promising, I don't think that this should result in a widespread implementation of Mediterranean diet in post-ablation populations. But you saw that there are other benefits of this dietary pattern, so it can be recommended for our patients."

The Mediterranean diet has been found to be one of the most heart-healthy diets, with its emphasis on vegetable, fruit, fish, and nut intake. However, Afib management guidelines recommend weight reduction (which the diet in PREDIMAR did not achieve) and limited or no alcohol intake (wine is considered part of the Mediterranean diet).

One big question is how the intervention would have fared in a population more like that of the U.S., with a less Mediterranean-like usual diet and higher rates of obesity, noted HRS session moderator Andrea Russo, MD, of Cooper University Hospital in Camden, New Jersey. "Maybe we could have a greater impact on outcomes," she told 麻豆传媒. "We are really underutilizing the lifestyle risk factor modifications in the U.S. in general."

There was a solid basis for the trial, Alberts noted, pointing to some evidence for an anti-inflammatory impact of the Mediterranean diet and a signal for Afib recurrence prevention in the PREDIMED trial. That prior trial -- the main results of which showed a high cardiovascular risk population had lower incidence of major cardiovascular events on a Mediterranean diet supplemented with extra-virgin olive oil or nuts compared with randomization to a reduced-fat diet -- had been retracted due to data issues, but was with similar findings.

was designed to follow up on the suggestion from PREDIMED. It included 720 patients, enrolled at four hospitals in Spain while getting catheter ablation for Afib, who were randomized to a diet maintained for 2 years. The remote intervention involved periodic phone calls by a dietitian and free provision of 2 L of extra-virgin olive oil at follow-up every 3 months, along with weight, Holter ECG, and portable cardiac rhythm monitoring measurements. The control group got a delayed intervention after trial completion and were to maintain their usual diet during the trial.

Overall Mediterranean dietary adherence scores already averaged 7.2 to 7.8 on the 13-point scale (excluding the question on wine consumption) at baseline; the intervention boosted the average to about 11 points.

For the primary endpoint, 18-month cumulative incidence of tachyarrhythmia recurrence was 28.6 cases per 1,000 person-years in the control group and 24.4 per 1,000 person-years in the intervention group. Among paroxysmal Afib patients, those rates were 24.9 and 16.6 per 1,000 person-years, respectively.

In the subgroup analyses, no difference was seen among patients with persistent Afib.

Despite the overall neutral result, Russo noted that the intervention at least appears safe, with all the hazard ratios trending in the favorable direction.

She concurred with Barrio-Lopez, who concluded: "This dietary pattern can be universally implemented and could be recommended to patients with AF after an ablation procedure to avoid arrhythmia recurrences."

While Alberts didn't necessarily agree, she called the trial a success in one regard: "It shows us that we can do dietary interventions at scale in patients post-ablation. And given the impact of obesity and weight reduction on AF, I think future trials should incorporate energy reduced Mediterranean diet and maybe avoiding the alcohol part of it to have greater benefits on AF recurrence."

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