ASE: Echo parameter can predict death after mitral valve surgery
The right ventricular (RV) basal diastolic dimension is an echocardiography parameter that can independently assess mortality in patients undergoing mitral valve surgery, according to a study presented this week at the 21st annual scientific sessions of the American Society of Echocardiography (ASE) meeting in San Diego.

Current models used to predict heart valve surgery mortality are based on clinical preoperative risk factors and observation of left ventricular function. However, the researchers noted that right ventricular parameters are currently not included in the evaluation.

Venkatesh Y. Anjan, MD, of Northwestern University’s Feinberg School of Medicine in Chicago, and colleagues investigated the prognostic impact of preoperative RV dimension or size among other factors to predict late mortality in patients undergoing mitral valve surgery.

The investigators analyzed 758 patients undergoing mitral valve surgery. The all-cause, long-term mortality was 11 percent in three years of follow-up; and all 87 patients who died were matched to 171 who survived as living controls. Therefore, the researchers analyzed the preoperative echocardiograms of 258 patients (mean age 67).

Anjan and colleagues found that the RV dimension and the left ventricular end systolic volume index were higher in the group that died. The RV dimension was 3.5 cm among the survivors, compared with 4.1 cm in the patients who died.

When controlling for the eight other variables (age, gender, history of congestive heart failure, NYHA III or IV, ejection fraction, Ambler score, concomitant tricuspid valve surgery, preoperative RV basal diastolic dimension, preoperative echo mean left ventricular end systolic volume index and preoperative echo TR severity), the investigators found Ambler score and RV dimension were the only two variables predictive of mortality.

After controlling for the Amber score, which the researchers said was a predictor of long-term mortality by “likelihood ratio test,” they found that RV dimension—and not the left ventricular end systolic volume index—was an independent predictor of late mortality. Conversely, they found that the Amber score was not an independent predictor when controlling for RV dimension or left ventricular end systolic volume index.

“The findings will help caregivers, patients and families make educated decisions about the appropriate timing of heart surgery,” said Anjan, adding the echocardiography could allow “for a more thorough assessment of the risk associated with performing mitral valve surgery.”

He added that the findings are “extremely important to surgeons and physicians who refer patients for this type of procedure."