Evolution of Clinical Features in Right Ventricular Outflow Tract Obstruction: Evidence From an Echocardiographic...

Long-term right ventricular outflow tract dysfunction can lead to right and left heart failure. Nonetheless, current data on the clinical characteristics of the right ventricular outflow tract obstruction (RVOTO) in China remain limited. This study analyzed the evolving trends in the observed proportion, etiology, spectrum, and interventions for RVOTO over the past 18 years from a single-center echocardiographic database.

A total of 10,234 RVOTO cases (17,451 records from 2003 to 2020) were included in the transthoracic echocardiography database in China. The RVOTO cases were divided into eight groups according to the different obstruction sites and disease types. Subsequently, RVOTO was categorized into three types: congenital, iatrogenic, and neither congenital nor iatrogenic. Moreover, congenital RVOTO was further classified into simple and complex congenital RVOTO. Next, we calculated the proportion of RVOTO patients who had received interventions. We analyzed the proportions of different types of RVOTO and the variation tendency.

During 2003-2008, 2009-2014, and 2015-2020, the observed proportion of RVOTO cases in the total echocardiographic cases decreased (3.2%, 2.1% and 1.8%, respectively; p < 0.001); the proportion of RVOTO with a congenital etiology also reduced, though as the dominant cause; meanwhile, the proportion of simple congenital RVOTO increased (48.5%, 52.4% and 67.3%, respectively; p < 0.001). As the two most common types of RVOTO, the proportion and number of valvular pulmonary stenosis (PS) increased, while the proportion of Fallot cases decreased. The number of RVOTO cases receiving surgical or transcatheter intervention and experiencing intervention-related severe pulmonary regurgitation (PR) or residual peripheral PS increased, although with a low probability of reoperation.

The clinical characteristics of RVOTO have undergone significant changes in China over the past two decades. After the RVOTO intervention, the increasing number of cases with severe PR or residual peripheral PS and a low possibility of reoperation signifies a future necessity for transcatheter pulmonary intervention.