Hemodynamic Changes after Surgical MAZE: Pulmonary Hypertension Secondary to Stiff Left Atrial Syndrome?

Abstract

Purpose Surgical MAZE procedure remains an effective treatment for atrial fibrillation but may result in hemodynamic changes with development of pulmonary hypertension (PH) secondary to left-sided heart disease, previously unreported in the literature. Methods and Materials A review of all patients undergoing MAZE procedure between 1/1/1999 and 12/31/2004 was performed. All patients had pre- and post-operative 2D echocardiograms (>3 months after MAZE). Estimated right ventricular systolic pressure (RVSP) cutoff ≥40 mm Hg on echocardiogram was suggestive of elevated right-sided pressures. Exclusion criteria included congenital heart disease, pre-operative RVSP >40 mm Hg, pre-op pulmonary hypertension, and mitral stenosis. Right heart catheterization was performed on patients with unexplained dyspnea in post-operative setting. Results Forty-one patients (26 males) with an average age of 63±10 years met inclusion criteria. The majority of patients (26/41, 63%) had post-op RVSP ≥40 mm Hg. Median pre-op RVSP was 32 mm Hg (IQ 27;37) with an increase in post-op RVSP to 41 mm Hg (IQ 33;58). Increase in RVSP was significant at 5 years (13±16 mm Hg; p=0.0005) post-Maze corresponding with an increase in RV size at 5 years and worsening RV systolic function. Eight patients underwent right heart catheterization. Mean RVSP was 53±13 mm Hg with a right atrial pressure of 14 ± mm Hg. Mean pulmonary artery pressure was 35±7 mm Hg with mean pulmonary capillary wedge pressure of 19±5 mm Hg and mean v wave of 27±6 mm Hg. Mean transpulmonary gradient was 16±6 mm Hg. Development of PH adversely impacted 10-year survival (p=0.03). Conclusions Surgical MAZE can by complicated by PH seen both noninvasively and invasively. The hemodynamic pathophysiology is mediated by left atrial noncompliance or Stiff Left Atrial Syndrome and may be a significant complication following surgical MAZE procedure, warranting further investigation.