Afterload mismatch after MitraClip insertion for functional mitral regurgitation.
Afterload mismatch, defined as acute impairment of left ventricular function after mitral surgery, is a major issue in patients with low ejection fraction and functional mitral regurgitation (FMR). Safety and efficacy of MitraClip therapy have been assessed in randomized trials, but limited data on its acute hemodynamic effects are available. This study aimed to investigate the incidence and prognostic role of afterload mismatch in patients affected by FMR treated with MitraClip therapy. We retrospectively analyzed patients affected by FMR and submitted to MitraClip therapy from October 2008 to December 2012. Patients were assigned to 2 groups according to the occurrence of the afterload mismatch: patients with afterload mismatch (AM+) and without afterload mismatch (AM-). Of 73 patients, 19 (26%) experienced afterload mismatch in the early postoperative period. Among preoperative variables, end-diastolic diameter (71 ± 8 vs 67 ± 7 mm, p = 0.02) and end-systolic diameter (57 ± 9 vs 53 ± 7 mm, p = 0.04) were both significantly larger in AM+ group. An increased incidence of right ventricular dysfunction (68% vs 31%, p = 0.049) and pulmonary hypertension (49 ± 10 vs 40 ± 10 mm Hg, p = 0.0009) was found in AM+ group. Before hospital discharge, left ventricular ejection fraction (LVEF) became similar in both groups (31 ± 9% vs 33 ± 11%, p = 0.65). Long-term survival was comparable between the 2 groups (p = 0.44). A low LVEF in the early postoperative period (LVEF <17%) was significantly associated with higher mortality rate in long-term follow-up (p = 0.048). In conclusion, reduction of mitral regurgitation with MitraClip can cause afterload mismatch; however, this phenomenon is transient, without long-term prognostic implications.
Department of Cardiovascular and Thoracic Surgery, Cardiovascular Anesthesia and Intensive Care, San Raffaele Hospital, Milan, Italy.
Giulio
G
Melisurgo
Department of Cardiology, San Raffaele Hospital, Milan, Italy. Electronic address: ajello.silvia@hsr.it.
Silvia
S
Ajello
Department of Cardiovascular and Thoracic Surgery, Cardiovascular Anesthesia and Intensive Care, San Raffaele Hospital, Milan, Italy.
Federico
F
Pappalardo
Department of Cardiac Surgery, San Raffaele Hospital, Milan, Italy.
Andrea
A
Guidotti
Department of Cardiology, San Raffaele Hospital, Milan, Italy.
Eustachio
E
Agricola
Interventional Cardiology Unit, San Raffaele Hospital, Milan, Italy.
Masanori
M
Kawaguchi
Interventional Cardiology Unit, San Raffaele Hospital, Milan, Italy.
Azeem
A
Latib
Department of Cardiovascular and Thoracic Surgery, Cardiovascular Anesthesia and Intensive Care, San Raffaele Hospital, Milan, Italy.
Remo Daniel
RD
Covello
Department of Cardiac Surgery, San Raffaele Hospital, Milan, Italy.
Paolo
P
Denti
Department of Cardiovascular and Thoracic Surgery, Cardiovascular Anesthesia and Intensive Care, San Raffaele Hospital, Milan, Italy.
Alberto
A
Zangrillo
Department of Cardiac Surgery, San Raffaele Hospital, Milan, Italy.
Ottavio
O
Alfieri
Department of Cardiovascular Surgery, UniversitätsSpital Zürich, Switzerland.
Francesco
F
Maisano
D000368:Aged; D004452:Echocardiography; D005260:Female; D005500:Follow-Up Studies; D006350:Heart Valve Prosthesis / Q000009:adverse effects*; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008943:Mitral Valve / Q000601:surgery*; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D011184:Postoperative Period; D011379:Prognosis; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D013318:Stroke Volume; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D016277:Ventricular Function, Left / Q000502:physiology*