Greater operator, hospital mitral valve surgery volume tied to reduced mortality, more repair

SAN FRANCISCO — Higher operator and hospital volume conferred better results for 30-day operative mortality, successful repair of primary mitral regurgitation and 1-year mortality, according to a presentation at TCT 2019.

Vinay Badhwar, MD, FACS, FACC, Gordon F. Murray Professor and Chair in the department of cardiovascular and thoracic surgery at West Virginia University in Morgantown, and colleagues analyzed data from 55,311 patients with primary mitral regurgitation from the Society of Thoracic Surgeons Adult Cardiac Surgery Database. Data were linked to CMS for outcomes at 1 year.

The primary outcome was operative mortality of isolated mitral valve surgery for the treatment of primary mitral regurgitation. Secondary outcomes included the successful repair rate of primary mitral regurgitation; a 30-day composite outcome of morbidity/mortality; and reoperation, mortality and HF rehospitalization at 1 year.

Hospitals were categorized into volume quartiles. Those in the lowest quartiles performed an estimated 11 cases per year and those in the highest quartiles performed greater than 46 cases per year, according to the press conference. Surgeons were also placed into quartiles, with the lowest quartile performing less than six cases per year and the highest quartile performing greater than 25 cases per year.

Compared with patients in the highest volume quartile, those in the lowest volume quartiles were more likely to have no insurance (4.04% vs. 2.35%; P < .001), were black or Hispanic (14.8% vs. 10.2%; P < .001) and had NYHA class III/IV symptoms (31.9% vs. 23.8%; P < .0001). The overall mitral valve repair rate for primary mitral regurgitation was 81%. When assessed by quartiles, patients in the highest quartile had a repair rate of 84.5% vs. 63.8% for those in the lowest quartile (P < .0001). Patients in the highest-volume quartiles were more likely to have NYHA class I symptoms compared with those in the lowest volume quartiles (1.8% vs. 4.1%; P < .0001), the referrals of class I patients were still less than 5% despite increased repair rates.

“Patients that meet guideline criteria that have severe primary mitral insufficiency appear to have increased access to quality valve repair than was previously estimated," Badhwar said during the press conference. "Yet, patients continue to be referred late when symptoms are more advanced, particularly even in the highest-volume centers.”

With regard to hospital-level outcomes, there was a clear inflection point at approximately 75 cases when assessed risk-adjusted operative mortality at 30 days. Outcomes were similar when surgeon-level outcomes were analyzed, with an inflection point seen at an estimated 35 cases.

Among the hospitals in the study, 14% performed at least 75 cases per year and among the surgeons, 13% performed at least 35 cases per year.

“These findings may have implications to further inform guideline-directed efforts to define access to experienced hospitals and surgeons for the treatment for primary mitral insufficiency or advanced complex disease,” Badhwar said during the press conference. – by Darlene Dobkowski

Reference:

Badhwar V, et al. Late-Breaking Science 2. Presented at: TCT Scientific Symposium; Sept. 25-29, 2019; San Francisco.

Disclosure: Badhwar reports no relevant financial disclosures.