Patient selection, data collection, endpoints
This study was conducted in accordance with the “Guidelines for
reporting mortality and morbidity after cardiac valve
interventions”[13]. Overall methods and study design for this
cohort of patients have been previously reported[14]. Briefly, this
was a retrospective cohort study of consecutive patients undergoing MVr
at a single institution between February 2004 and July 2015. The
follow-up period closed July 2016. Prior to 2004, minimally invasive
mitral repair was not routinely done and therefore these cases were
excluded. MVr was defined as MV reconstruction with or without an
annuloplasty ring. Patients who underwent MV annuloplasty alone (without
valve reconstruction), were excluded. Patients undergoing concomitant
cardiac procedures were included. The institutional review board of the
University of Southern California Health Sciences Campus approved this
study (HS-15-00509) and waived the requirement for patient consent. The
senior author performed over 85% of the total procedures, and nearly
100% of the minimally invasive procedures.
Patients were divided into two groups based on the operative approach to
MVr (Group 1 - MVr via small right anterior thoracotomy, RAT; Group 2 –
MVr via full sternotomy, ST). Baseline characteristics and perioperative
outcomes were identified through our institutional database. The primary
endpoints were mortality, need for MV reoperation, and the progression
of mitral regurgitation (MR). Follow up TTEs were obtained at the
discretion of the physician. MR was coded 0 to 4 based on echocardiogram
reports (0 = none, 1 = trace, 2 = mild, 2.5 = mild-to-moderate, 3 =
moderate, 3.5 = moderate-to-severe, 4 = severe). Progression of MR was
defined as worsening of MR by more than 2 grades.