Conference Coverage

Outcomes/costs similar for minimally invasive vs. sternotomy-based mitral surgery


Key clinical point: Outcomes and costs of minimally invasive mitral surgery are similar to that of conventional sternotomy for mitral valve surgery.

Major finding: Mortality rates of 1.3% and major morbidity rates of 11% were similar in both groups.

Data source: Propensity-matched analysis of 479 patients who had a primary mitral valve operation from January 2010 to June 2016 at the University of Virginia.

Disclosures: Dr. Hawkins reported no financial disclosures. Coauthor Dr. Gorav Ailawadi disclosed consulting agreements with Edwards Lifesciences, Abbott, Medtronic, and AtriCure.




– 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 of the University of Virginia, Charlottesville
Dr. Gorav Ailawadi
Minimally invasive surgery often is criticized as a more expensive approach with little benefit, prompting the idea for this analysis, said coauthor Gorav Ailawadi, MD, also of the University of Virginia. The analysis involved records of 479 patients in the institutional Society of Thoracic Surgery database who had a primary mitral valve operation at the University of Virginia from January 2012 to June 2016. The researchers extracted propensity-matched cohorts of 93 each who had conventional and minimally invasive mitral operations. The cost analysis involved pairing the procedures with institutional financial records.

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.

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