Detrimental effects of elevated transpulmonary gradient on outcomes following restrictive mitral annuloplasty in patients with pre-existing pulmonary hypertension.

Abstract

BACKGROUND:

This study retrospectively examined the association between elevated trans-pulmonary gradient (TPG), which reflects pre-capillary contribution to pulmonary hypertension (PH), and postoperative pulmonary hemodynamics and outcomes following restrictive mitral annuloplasty (RMA) in patients with pre-existing PH.

METHODS:

Pre- and postoperative (1 month) cardiac catheterization was performed in 64 patients with severely impaired left ventricular function (i.e., ejection fraction ≤40%) and pre-existing PH (mean pulmonary artery pressure (PAP) ≥25 mmHg) who underwent RMA. Patients were segregated into two groups: low TPG (≤12 mmHg) and elevated TPG (>12 mmHg). The mean follow-up period was 54±27 months. The primary outcome seen was a change in pulmonary hemodynamics after RMA; secondary outcomes were composite adverse events, including all-cause mortality and readmission for heart failure.

RESULTS:

Compared to the low TPG group, patients in the elevated TPG group were more likely to show a postoperative mean PAP of ≥25 mmHg (84% vs. 38%), TPG of >12 mmHg (79% vs. 11%), and pulmonary vascular resistance of ≥240 dynes/sec/cm-5 (84% vs. 6.7%) (all P<0.001), although both groups showed comparable degrees of mitral regurgitation improvement. Serial echocardiography demonstrated that Doppler-derived systolic PAP, which once decreased in both groups, remained stable in the low group while steadily increasing in the elevated group (group effect P<0.001). Patients with elevated TPG had lower freedom from composite adverse events (5-year, 20% vs. 70%, P=0.003). After adjusting for baseline covariates, the elevated TPG was independently associated with increased risk of adverse events (adjusted hazard ratio 2.9, 95% CI: 1.2-6.9, P=0.017).

CONCLUSIONS:

Elevated TPG negatively affects postoperative pulmonary hemodynamics and late outcomes in patients with advanced cardiomyopathy and pre-existing PH who have undergone RMA. These findings suggest that the assessment of TPG should be included in post-RMA risk stratification.

• Authors: Satoshi Kainuma, Koichi Toda, Shigeru Miyagawa, Yasushi Yoshikawa, Hiroki Hata, Daisuke Yoshioka, Takuji Kawamura, Ai Kawamura, Noriyuki Kashiyama, Takayoshi Ueno, Toru Kuratani, Toshihiro Funatsu, Haruhiko Kondoh, Takafumi Masai, Arudo Hiraoka, Taichi Sakaguchi, Hidenori Yoshitaka, Takashi Daimon, Kazuhiro Taniguchi, Yoshiki Sawa, Osaka Cardiovascular Surgery Research (OSCAR) Group
• Journal: Journal of thoracic disease (J Thorac Dis) Vol. 13 Issue 5 Pg. 2746-2757 (May 2021) ISSN: 2072-1439 [Print] China
• PMID: 34164167 (Publication Type: Journal Article)
• Copyright: 2021 Journal of Thoracic Disease. All rights reserved.