Patients who received aortic valve repair or replacement (AVR) based on Class II indications fared better than those who underwent surgery for Class I triggers in a single-center study, suggesting earlier intervention may be warranted in asymptomatic individuals with chronic aortic regurgitation.
The guideline recommendations on surgical interventions for severe aortic regurgitation are derived mostly from studies of patients who were treated more than 20 years ago, a group of Mayo Clinic researchers wrote in the Journal of the American College of Cardiology.
To offer more recent research on the topic—and to evaluate the indications for surgery from the 2014 U.S. valvular heart disease guidelines—the researchers tracked the outcomes of 748 patients treated for moderate-to-severe aortic regurgitation from 2006 to 2017 at Mayo Clinic in Rochester, Minnesota.
Participants were 58 years old on average, 82 percent of them were men and none had previous heart surgery, myocardial infarction or overt coronary artery disease. Fifty-two percent of patients were managed with medications, while the remaining 48 percent received AVR.
Of the 361 patients who underwent AVR, 79 percent met Class I indications for surgery, including showing symptoms or having a left ventricular ejection fraction (LVEF) below 50 percent. Fourteen percent had echocardiography-derived Class II indications, which include a LV end-systolic dimension index (LVESDi) greater than 25 mm/m2, a LVESD above 50 mm and LV end-diastolic dimension above 65 mm.
Over a median follow-up of 4.9 years, lead author Li-Tan Yang, MD, and colleagues found LVESDi was the only echocardiographic parameter independently associated with all-cause mortality. And even patients below the guideline-recommended, Class II threshold were found to be at increased risk; compared to patients with LVESDi below 20 mm/m2, those between 20 and 25 mm/m2 were 53 percent more likely to die during follow-up. Patients with LVESDi at or above 25 mm/m2 demonstrated 2.23 times the risk.
“Our results highlight the importance of LVESDi, as has been previously recommended,” Yang et al. wrote. “Because it is age, sex, and body size neutral, it can correctly assess the severity of LV enlargement, and was associated with all-cause death. Importantly, late mortality was increased in patients who had LVESDi 20 to 25 mm/m2, values below the threshold for surgery in current guidelines.”
AVR was associated with better survival than medication alone across the LVESDi ranges, but the authors found post-operative survival was even better when patients underwent surgery for Class II indications rather than Class I triggers.
“It seems reasonable that referral for AVR should be considered in asymptomatic patients with Class II surgical triggers,” Yang and colleagues wrote. “To move the needle toward better outcome, our data suggest that AVR might be considered relatively early, before LVESDi >25 mm/m2 and when LVESDi progressively increases beyond 20 mm/m2.”
The authors noted the single-center design was a limitation of their study, and said the results at their high-volume, tertiary center might not be applicable to lower-volume centers. Also, quality-of-life outcomes weren’t assessed and there were no data about changes in LV dimensions or medication regimens during follow-up, which could have impacted outcomes.