Aortic Valve Surgery Risk Tied to Hypertension : Operative mortality reached 9% in those with pulmonary hypertension and 5% in those without.

Major Finding: Patients with pulmonary hypertension had a significant 50% increased risk of operative death during aortic valve replacement. Patients with severe pulmonary hypertension (60 mm Hg or greater) following aortic valve replacement had a significantly worse 5-year survival, 45%, compared with 78% survival in patients with no pulmonary hypertension following valve replacement.

Data Source: The 1,080 patients who underwent open surgical aortic valve replacement at Washington University, St. Louis, during 1996-2009.

Disclosures: Dr. Melby said that he had no disclosures. Dr. Ralph J. Damiano Jr., a study coauthor, is a consultant to AtriCure, Medtronic, and ATS Medical, and has received research support from Estech and Edwards Lifesciences.

TORONTO — Pulmonary hypertension poses a risk to patients undergoing aortic valve replacement, based on a review of more than 1,000 patients who underwent open aortic valve surgery at one U.S. center during 1996-2009.

Patients who entered surgery with severe pulmonary hypertension, 60 mm Hg or greater, were at greatest risk, and did not have their severe status resolved to a lower level of pulmonary hypertension by surgery, Dr. Spencer J. Melby said at the meeting.

Roughly 10% of the 1,080 patients in the series had severe pulmonary hypertension prior to their aortic valve replacement and continued to have severe pulmonary hypertension post surgery, said Dr. Melby, a cardiothoracic surgeon at Washington University, St. Louis.

He and his associates have begun to treat patients with refractory pulmonary hypertension following valve replacement with a regimen designed to lower their pulmonary pressure, such as inhaled nitric oxide or intravenous epoprostenol, but so far the group does not have data on the impact of such treatment on the long-term outcomes of these patients.

Another benefit of knowing the increased risk faced by patients with pulmonary hypertension is in counseling. “You can decide if [aortic valve replacement] surgery is the right thing to do” in individual patients, Dr. Melby said in an interview. “We're not suggesting that patients with severe pulmonary hypertension not undergo aortic valve replacement, but we need to better understand their risk.” Several prior reports documented a pulmonary hypertension prevalence of 30%-70% in patients undergoing aortic valve replacement, he noted.

The review involved 506 patients with pulmonary hypertension (47%) and 574 patients who were free of pulmonary hypertension when they underwent aortic valve replacement. The patient's average age was 71, and two-thirds had New York Heart Association class III or IV heart failure; patients with pulmonary hypertension were slightly older (average age 72), and had a higher prevalence, 77%, of severe heart failure.

Operative mortality reached 9% in the pulmonary hypertension subgroup and 5% in the patients without pulmonary hypertension, a statistically significant difference. The pulmonary hypertension group also had a significantly higher need for prolonged ventilation, 26%; increased length of stay, an average of 8 days; and a greater need for intra-arterial balloon pump, 11%. In a multivariate analysis, pulmonary hypertension was linked with a significant 50% increased risk for operative death. Other significant factors in this analysis included renal failure, diabetes, and prior cardiac pump bypass.

Among the subgroup with pulmonary hypertension, roughly a third had mild hypertension, 35-44 mm Hg; a third had a moderate level of 45-59 mm Hg; and about a third had severe pulmonary hypertension of 60 mm Hg or greater. Many patients in the moderate and severe subgroups had substantial drops in pulmonary pressure following aortic valve replacement, but other patients did not.

Average follow-up reached 3.4 years in the patients with pulmonary hypertension at baseline, and 4.4 years in the patients without pulmonary hypertension at the time of their surgery. Severity of preoperative pulmonary pressure functioned as a significant risk factor for long-term survival. The researchers found a 5-year, actuarial survival rate of 60% in patients without pulmonary hypertension, 68% in those with mild pulmonary hypertension, 57% in patients with moderate pulmonary hypertension, and 52% in those with severe pulmonary hypertension at surgery.

Severity of pulmonary hypertension following valve replacement acted as an even stronger determinant of long-term survival. Patients with no pulmonary hypertension following surgery had 78% actuarial 5-year survival. Patients with mild hypertension after surgery had a 77% 5-year survival rate, those with moderate hypertension after surgery had a 64% 5-year survival rate, and patients with severe postoperative pulmonary hypertension had a 45% 5-year survival rate.