Effectiveness of positive expiratory pressure training in patients after reconstruction of postinfarction left ventricular aneurysm and coronary artery bypass grafting: a prospective study

INTRODUCTION. Positive expiratory pressure (PEP) training is widely used in respiratory rehabilitation for patients after coronary artery bypass grafting (CABG). However, its effectiveness in patients after left ventricular geometric reconstruction (LVGR) with underlying chronic heart failure (CHF) has not been fully investigated. AIM. To study the effectiveness of PEP-training in patients after LVGR with baseline CHF in comparison with patients after CABG in the early postoperative period. MATERIALS AND METHODS. The study included 40 patients: Group I (n = 20) — patients after LVGR + CABG, and Group II (n = 20) — patients after CABG. The respiratory rehabilitation protocol was identical in both groups. Assessment was performed at three time points (I — before surgery, II — at transfer from the intensive care unit, III — discharge) and included spirometry, echocardiography, integral rheography of the body, and 24-hour pulse oximetry. RESULTS. At baseline, Group I had significantly worse parameters in both cardiac (ejection fraction: 44.6 % [40.72; 48.00] vs 54.4 % [51.30; 59.92]; p 0.001) and respiratory function (forced vital capacity: 86.10 % [81.60; 91.42] vs 98.4 % [93.07; 104.98]; p 0.001). After the surgical intervention, a comparable negative trend in respiratory system parameters was observed in both groups, with a predominance of gas exchange disturbances in Group I (p 0.001). By the time of discharge, spirometry parameters recovered comparably in both groups. However, Group I, unlike Group II, exhibited persistent significant systemic hypervolemia (extracellular fluid water: 26.90 [23.45; 27.60] L vs 19.25 [16.70; 22.10] L; p 0.001) and sleep-related gas exchange disturbances (oxygen desaturation index: 8.45 [7.75; 9.18] vs 5.80 [5.17; 7.62]; p 0.001). DISCUSSION. Comparable spirometry recovery by discharge, despite the initially worse pulmonary function in Group I, indicates the effectiveness of PEP-training in patients with varying degrees of CHF. Persistent hypervolemia and nocturnal desaturation in Group I are likely related to nocturnal rostral fluid shift and the absence of an ejection fraction increase after surgical remodeling. The correlation between ejection fraction and spirometry parameters supports the leading role of baseline CHF severity in postoperative recovery. CONCLUSION. PEP-training is an effective method for restoring pulmonary function in patients after LVGR and CABG. However, the presence of severe baseline CHF requires a multimodal approach, which also includes the correction of fluid balance and sleep-disordered breathing.