Bergsten Johannes, Baron Tomasz, Hedin Eva-Maria, Hadziosmanovic Nermin, Malinovschi Andrei, Flachskampf Frank A
Department of Heart and Lung Diseases, Uppsala University Hospital, Uppsala, Sweden.
Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
PLoS One. 2025 Jul 9;20(7):e0326418. doi: 10.1371/journal.pone.0326418. eCollection 2025.
Patients with severe primary mitral regurgitation (PMR) remain asymptomatic at first. In the long term, however, severe PMR leads to cardiac decompensation. Exercise testing in asymptomatic PMR is recommended in selected patients by guidelines. Cardiopulmonary exercise testing (CPET), which additionally measures ventilation (VE), oxygen consumption (VO2) and carbon dioxide production (VCO2), has been scarcely studied in PMR. We hypothesized that CPET might have prognostic value in asymptomatic PMR and therefore studied if CPET, including assessment of ventilation efficiency, has prognostic value for asymptomatic patients with severe PMR.
Asymptomatic patients with severe PMR were prospectively recruited between 2013 and 2018. Exclusion criteria were coronary artery disease, chronic kidney disease, diabetes mellitus, concomitant valve disease, symptomatic lung disease or class 1 recommendation for valvular surgery. Echocardiography and serial CPET were conducted at one university hospital in Sweden. Primary outcome was mitral valve intervention.
Forty-eight patients were recruited to the study. Median follow-up period was 4.4 (2.1-6.9) years, during which 28 (58%) patients underwent mitral valve surgery. Ventilation efficiency, the relationship of VE to VCO2 during CPET, predicted surgical treatment of the mitral valve. Increased VE/VCO2 ratio at the anaerobic threshold had the highest predictive value, remaining an independent predictor after adjusting for impaired VO2 at peak exercise (HR 4.42 (1.52-12.92), p = 0.007) and echocardiographic thresholds for left ventricular and atrial remodelling, as defined by current guideline-based recommendation for intervention (HR 3.72 (1.41-9.82), p = 0.008).
Impaired ventilatory efficiency, but not peak VO2, predicted surgical treatment of the mitral valve in asymptomatic patients with severe PMR. Ventilatory efficiency, a CPET index less dependent on peak exercise performance, may be a new useful tool in risk stratification.
重度原发性二尖瓣反流（PMR）患者起初通常无症状。然而，从长期来看，重度PMR会导致心脏失代偿。指南建议对部分无症状PMR患者进行运动测试。心肺运动测试（CPET）可额外测量通气量（VE）、耗氧量（VO2）和二氧化碳生成量（VCO2），但在PMR中的研究较少。我们推测CPET可能对无症状PMR具有预后价值，因此研究了包括通气效率评估在内的CPET对无症状重度PMR患者是否具有预后价值。
2013年至2018年期间前瞻性招募无症状重度PMR患者。排除标准包括冠状动脉疾病、慢性肾病、糖尿病、合并瓣膜疾病、有症状的肺部疾病或瓣膜手术的1类推荐。在瑞典的一家大学医院进行超声心动图检查和系列CPET。主要结局是二尖瓣干预。
48名患者纳入研究。中位随访期为4.4（2.1 - 6.9）年，在此期间28名（58%）患者接受了二尖瓣手术。通气效率，即CPET期间VE与VCO2的关系，可预测二尖瓣的手术治疗。无氧阈值时VE/VCO2比值升高具有最高预测价值，在调整峰值运动时VO2受损以及根据当前基于指南的干预推荐所定义的左心室和心房重构的超声心动图阈值后，仍为独立预测因子（HR 4.42（1.52 - 12.92），p = 0.007）以及（HR 3.72（1.41 - 9.82），p = 0.008）。
通气效率受损而非峰值VO2，可预测无症状重度PMR患者的二尖瓣手术治疗。通气效率作为一个较少依赖峰值运动表现的CPET指标，可能是风险分层中的一个新的有用工具。
