Predictors of low cardiac output after isolated pericardiectomy: an observational study

BACKGROUND: Low cardiac output is the main cause of perioperative death after pericardiectomy for constrictive pericarditis. We investigated the associated risk factors and consequences. METHODS: We selected constrictive pericarditis patients undergoing isolated pericardiectomy from January 2013 to January 2021. Postoperative low cardiac output was defined as requiring mechanical circulatory support or more than one inotrope to maintain a cardiac index > 2.2 L •min(−1) •m(−2) without hypoperfusion, despite adequate filling status. Uni- and multivariable analysis were used to identify factors associated with low cardiac output. Cox regression was used to identify factors associated with length of hospital stay. RESULTS: Among 212 patients with complete data, 55 (25.9%) developed low cardiac output within postoperative day 1 (quartiles 1 and 2), which caused seven of the nine perioperative deaths. The rates of atrial arrhythmia, renal dysfunction, hypoalbuminemia, modest-to-severe hyponatremia, and hyperbilirubinemia caused by constrictive pericarditis were 9.4%, 12.3%, 49.1%, 10.4%, and 81.6%. The mean preoperative central venous pressure and cardiac index were 18 ± 5 cmH(2)O and 1.87 ± 0.45 L•min(−1)•m(−2). Univariable analysis showed that low cardiac output patients had higher rates of atrial arrhythmia (OR 3.32 [1.35, 8.17], P = 0.007), renal dysfunction (OR 4.24 [1.94, 9.25], P < 0.001), hypoalbuminemia (OR 1.99 [1.06, 3.73], P = 0.031) and hyponatremia (OR 6.36 [2.50, 16.20], P < 0.001), greater E peak velocity variation (difference 2.8 [0.7, 5.0], P = 0.011), higher central venous pressure (difference 3 [2,5] cmH(2)O, P < 0.001) and lower cardiac index (difference − 0.27 [− 0.41, − 0.14] L•min(−1)•m(−2), P < 0.001) than patients without low cardiac output. Multivariable regression showed that atrial arrhythmia (OR 4.04 [1.36, 12.02], P = 0.012), renal dysfunction (OR 2.64 [1.07, 6.50], P = 0.035), hyponatremia (OR 3.49 [1.19, 10.24], P = 0.023), high central venous pressure (OR 1.17 [1.08, 1.27], P < 0.001), and low cardiac index (OR 0.36 [0.14, 0.92], P = 0.032) were associated with low cardiac output (AUC 0.79 [0.72–0.86], P < 0.001). Cox regression analysis showed that hyperbilirubinemia (HR 0.66 [0.46, 0.94], P = 0.022), renal dysfunction (HR 0.51 [0.33, 0.77], P = 0.002), and low cardiac output (HR 0.42 [0.29, 0.59], P < 0.001) were associated with length of hospital stay. CONCLUSIONS: Early recognition and management of hyponatremia, renal dysfunction, fluid retention, and hyperbilirubinemia may benefit constrictive pericarditis patients after pericardiectomy.