Skip to content

Outcomes of Elective Cardiac Surgery at Mass General Not Affected by Start Time

Key findings

  • In a retrospective cohort of 2,460 patients, a late start to elective cardiac surgery (after 3 pm) was not associated with higher total hospital costs compared with cases performed earlier in the day
  • Analysis of a propensity-matched subcohort showed that a late start was not associated with clinically significant differences in postoperative outcomes or operative mortality
  • The findings suggest the timing of cardiac surgery is not a critical determinant of outcomes, but the results may be attributable to the resources available at a large quaternary academic center regardless of time of day

The well-documented ''after-hours'' effect in hospital care—the combined impact of patient handoffs, differences in staff expertise and resource limitations during evening and weekend hours—is a particular concern in cardiac surgery. Complex procedures in high-risk patients require a highly reliable team of subspecialty-dedicated surgeons, anesthesiologists, intensivists, perfusionists and nurses.

Studies investigating the effects of after-hours care in cardiac surgery have had conflicting results. Some, but not all, have shown that starting nonemergent cases later in the day is associated with increased mortality and higher hospital costs.

After retrospectively exploring the situation at Massachusetts General Hospital, clinical surgical fellow Andrea Axtell, MD, MPHThoralf M. Sundt III, MD, chief of Cardiac Surgery in the Corrigan Minehan Heart Center, and colleagues report no negative effect of a late start time on patient outcomes or costs. However, in The Journal of Thoracic and Cardiovascular Surgery, they explain why their findings may not be generalizable to all hospitals.

Study Design

The researchers studied 2,460 adults who underwent elective coronary artery bypass graft or an open valve procedure at Mass General between July 2011 and March 2018. Start time was dichotomized as "early" (incision occurring between 7 am and 3 pm) or ''late" (incision occurring after 3 pm).

352 patients (10%) had a late start time. Of those, 301 (85%) were the second consecutive operation performed by the surgeon that day and 20 (6%) were the surgeon's third case of the day.

The primary study outcomes were operative mortality, defined as death occurring in hospital or within 30 days after surgery, and total hospital cost.

Propensity-Matched Analysis

The researchers generated a propensity-matched sample of 575 early-start patients and 352 late-start patients, closely matched in terms of age, sex, comorbidities, types of operations performed, use of an intra-aortic balloon pump, average duration of cardiopulmonary bypass and average aortic cross-clamp time.

There were no between-group differences in:

  • Operative mortality
  • Major postoperative complications
  • Median ICU length of stay
  • Median postoperative hospital length of stay
  • Total hospital costs
  • Operating room costs

On multivariable analysis of the entire cohort, a late start was not associated with increased hospital costs when adjusted for patient comorbidities and operative characteristics.

The Importance of Good Systems

The conflicting outcomes in other studies of surgical start time may reflect variations in institutional protocols and resource availability. For example, at Mass General, a cardiac surgery procedure that starts after 3 pm is staffed by the same specialized cardiac anesthesia and cardiac-trained operating room nurses as earlier-starting cases, and the same anesthetic techniques are applied.

In addition, regardless of the time of day, patients are sent for recovery to a specialized cardiac ICU staffed around the clock by a cardiac intensivist, a cardiac surgery fellow, subspecialty-dedicated nurse practitioners and a respiratory therapist.

The study findings do not imply that after-hours surgery should be encouraged. Rather, they should be interpreted as demonstrating that elective cardiac surgery can be performed safely at any time of day—provided that dedicated resources and 24/7 subspecialized expertise are available.

The impact of after-hours surgery on team morale, surgeon ''burnout'' and staff retention were not assessed in this study but remain critical factors to be considered.

Learn more about Cardiac Surgery at Mass General

Refer a patient to the Corrigan Minehan Heart Center

Related topics


Extracorporeal membrane oxygenation is a "team sport," researchers at Massachusetts General Hospital say. In the largest single-center review of ECMO outcomes to date, they found that implementing a protocolized, multidisciplinary approach significantly improved in-hospital survival.


Patients scheduled for surgical aortic valve replacement who are older than 65 and have moderate to severe left atrial enlargement are at high risk of prolonged atrial fibrillation and should be considered for prophylactic surgical interventions.