Early surgery superior to rescue surgery for mitral regurgitation

Patients who underwent early surgery for mitral regurgitation were less likely to have postoperative mortality and heart failure compared with those who waited for rescue surgery, according to a Mayo Clinic analysis.

Lead researcher Maurice Enriquez-Sarano, MD, of the Mayo Clinic in Rochester, Minn., and colleagues examined 1,512 patients who underwent surgical correction of pure organic mitral regurgitation between 1990 and 2000. Results were published in The Journal of Thoracic and Cardiovascular Surgery on Aug. 11.

The researchers noted that guidelines in the U.S. typically define triggers to determine when patients should undergo surgery. If they have class I triggers such as heart failure symptoms, low left ventricular ejection fraction or large end-systolic dimension, they typically undergo immediate surgery. However, class II triggers such as atrial fibrillation, pulmonary hypertension or high mitral regurgitation provide for more leeway on when to operate.

Still, the researchers said the guidelines are based mostly on expert opinions, causing many to question the best timing for mitral regurgitation surgery.

In this study, the mean age was 64, and 66 percent of patients were men. At baseline, 35 percent of patients had heart failure symptoms and 27 percent had atrial fibrillation. The most common cause of mitral regurgitation was degenerative (86 percent of patients), followed by rheumatic (5 percent), endocarditic (5 percent) and miscellaneous organic (3 percent).

The researchers divided the patients into three groups: the first had class I triggers, the second had class II triggers and the third had severe mitral regurgitation and no other surgical triggers but underwent early surgery.

After adjusting for age, the mortality risk was nearly doubled in the class I group and increased by 40 percent in the class II group compared with the early surgery group. After 15 years, the survival rates were 42 percent, 53 percent and 70 percent, respectively.

The researchers also noted there was a 2.5 times increased risk for heart failure in the class I group and a 2 times increased heart failure risk in the class II group compared with the early surgery group.

The combined rates of heart failure and death were 65 percent in the class I group, 55 percent in the class II group and 37 percent in the early surgery group.

“Our study indicates that early repair should be preferred to rescue surgery in patients with mitral regurgitation,” Enriquez-Sarano said in a news release. “Guideline triggers for [mitral regurgitation] surgery based on symptoms and complications are linked to excess postoperative mortality and morbidity versus early surgery. Early surgery in this era of low operative risk and high repair rates provides the best long-term outcomes after [mitral regurgitation] surgery.”