NEW YORK – Minimally invasive mitral valve surgery provides outcomes that match those of conventional sternotomy without increasing use of resources, and lower costs after surgery offset potentially higher operation costs, according to a single-center, propensity-matched analysis of almost 500 patients presented at the meeting sponsored by the American Association for Thoracic Surgery.
“Minimally invasive mitral surgery has excellent outcomes with fewer transfusions and less time ventilated in this representative cohort,” said Robert Hawkins, MD, of the University of Virginia, Charlottesville, in reporting the results.
“While operative times were longer, surgical costs remained statistically similar, and minimally invasive mitral surgery was associated with similar total costs in more complex mitral cases.”
Dr. Gorav Ailawadi
Dr. Hawkins said this study included higher risk patients to attempt to overcome shortcomings of previously published reports that skewed toward lower-risk, highly selective mitral repairs for degenerative mitral disease. “They’re not really representative of the current state of minimally invasive mitral valve surgery as it currently stands in the higher risk patient population,” he said of previous studies.
Major outcomes were similar in both groups. “The mitral valve repair rate was about 81% for both groups, and the tricuspid valve repair rate was 8.8%,” Dr. Hawkins said. “About 35% had atrial fibrillation surgery, including both ablation and left atrial appendage ligation.”
Dr. Hawkins characterized outcomes in both surgical groups as “excellent,” and added, “The operative mortality rate was 1.3% and the major morbidity rate was 11% and not different between groups.”
Some key operative characteristics differed between the two groups. “As expected the cross clamp times and bypass times for the minimally invasive approaches were longer,” Dr. Hawkins said. Also, those who had minimally invasive mitral surgery had a “dramatic decrease” in transfusion rates.
With regard to resource utilization, minimally invasive surgery had longer operative times – an average of 291 minutes vs. 222 minutes (P less than .0001) – but similar or improved use of postoperative resources. “We see that the minimally invasive approach leads to decreased treatment and ancillary costs without a statistically significant difference in surgical costs despite the longer operative times,” Dr. Hawkins said.
However, he noted the high variability of total hospital costs in higher-risk populations complicate any head-to-head comparisons of resource utilization between the conventional and minimally invasive approaches, so the researchers attempted to drill down to identify predictors of resource use. Using a regression model, they found that minimally invasive approach may actually save money, although this finding was not statistically significant (–$1,524; P = 0.83).
“We see that the major drivers of costs are complications,” Dr. Hawkins said. “Morbidity and mortality led to a $54,000 cost increase, and the addition of tricuspid repair also led to about $60,000 higher costs, which is more likely related to higher risk and thus complications. The costs of higher-acuity cases are driven by the complications and not the approach.”
Dr. Hawkins reported no financial relationships. Dr. Ailawadi disclosed consulting agreements with Edwards Lifesciences, Abbott, Medtronic, and AtriCure.