Edge-to-edge repair for functional mitral regurgitation: an echocardiographic study of the hemodynamic consequences.
OBJECTIVE
The study aim was to characterize changes in mitral valve area and flow, and left ventricular (LV) size and function, following edge-to-edge (E-E) repair for severe functional mitral regurgitation (MR). The possibility that preoperative dobutamine stress echocardiography (DSE) might be used to predict post-repair recovery in LV function was also examined.


METHODS
Seventeen patients underwent preoperative transthoracic echocardiography (TTE) and DSE, intraoperative transesophageal echocardiography, and three-month postoperative TTE.


RESULTS
After repair, mitral valve area was reduced from 8.5 +/- 1.9 cm2 to 3.8 +/- 0.9 cm2 by planimetry (p < 0.0001) and to 2.9 +/- 0.9 cm2 by pressure half-time. Valve area by pressure half-time correlated with the planimetered area (r = +0.55), but was consistently lower (p = 0.004). Sixxteen of 17 patients had mean transmitral gradients <5 mmHg. Postoperative LV end-diastolic diameter improved from 72 +/- 11 to 64 +/- 10 mm (p < 0.01), and end-systolic diameter from 56 +/- 14 to 46 +/- 12 mm (p < 0.05). Mean ejection fraction improved from 25 +/- 12% before repair to 38 +/- 17% after repair (p < 0.02) in patients with evidence of LV function improvement on DSE, but was unchanged (15 +/- 5% versus 17 +/- 5%, p = NS) in patients without evidence of improvement. Postoperatively, 13 patients had no or mild MR, and two patients had moderate MR. There was one perioperative death.


CONCLUSIONS
E-E repair, in combination with ring annuloplasty, reduces LV cavity dimensions and functional MR severity, without causing significant valve stenosis. Improvement on DSE may predict those patients in whom EF will improve following repair.
Kinnaird
Tim D
TD
Cardiac Echo Laboratory, St. Paul's Hospital, and the University of British Columbia, Vancouver, BC, Canada.
Munt
Bradley I
BI
Ignaszewski
Andrew P
AP
Abel
James G
JG
Thompson
R Christopher
RC
D000328:Adult; D000368:Aged; D000714:Anastomosis, Surgical; D006348:Cardiac Surgical Procedures / Q000379:methods*; D015331:Cohort Studies; D004280:Dobutamine; D015150:Echocardiography, Doppler / Q000379:methods*; D017548:Echocardiography, Transesophageal / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006334:Heart Function Tests; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000000981:diagnostic imaging* / Q000601:surgery*; D016343:Monitoring, Intraoperative / Q000379:methods; D011184:Postoperative Period; D011300:Preoperative Care / Q000379:methods; D011379:Prognosis; D018570:Risk Assessment; D012720:Severity of Illness Index; D016896:Treatment Outcome; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging*
D004280:Dobutamine