High-risk mitral valve surgery: perioperative hemodynamic optimization with nesiritide (BNP)

Area of Science:

• Cardiology
• Cardiac Surgery
• Pharmacology

Background:

• Nesiritide, a recombinant brain-type natriuretic peptide (BNP), is known to decrease pulmonary arterial pressures and myocardial oxygen consumption while increasing coronary flow and urine output.
• Mitral valve (MV) surgery for severe mitral regurgitation (MR) in patients with impaired left ventricular function and pulmonary hypertension carries a high operative mortality risk.
• This study investigated the safety and efficacy of perioperative Nesiritide administration in such high-risk surgical candidates.

Purpose of the Study:

• To evaluate the safety and potential benefits of perioperative Nesiritide in patients undergoing MV surgery for severe MR with compromised cardiac function and pulmonary hypertension.
• To assess the impact of Nesiritide on key hemodynamic parameters and early surgical outcomes in this high-risk population.

Main Methods:

• A cohort of 14 high-risk patients (mean age 64, mean ejection fraction 36%) undergoing MV surgery (repairs or replacements) for severe MR received intravenous Nesiritide for a median of 24 hours preoperatively.
• The study included patients with severe pulmonary hypertension (mean systolic PA pressure 63 mm Hg) and significant comorbidities, with an expected mortality of 26% by EuroSCORE.
• Concomitant procedures such as tricuspid valve repair, coronary artery bypass grafting, and atrial maze procedures were frequently performed.

Main Results:

• The study achieved 0% operative mortality, a significant improvement compared to the expected risk.
• Nesiritide treatment led to a significant reduction in mean systolic pulmonary arterial pressure (from 63 to 39 mm Hg, p=0.0003), pulmonary capillary wedge pressure, and central venous pressure, along with a decrease in body weight.
• Postoperative median ventilation time was 14 hours, and other major hemodynamic parameters remained stable. The treatment was well-tolerated by all patients.

Conclusions:

• Perioperative Nesiritide administration is safe and appears to improve early outcomes in high-risk patients undergoing mitral valve surgery.
• The observed benefits may stem from improved ventricular loading conditions, including decreased pulmonary arterial pressures and enhanced diuresis, potentially augmented by a direct myocardial effect of BNP.
• Further prospective studies are warranted to fully elucidate the role of BNP in perioperative cardiac surgery management.