Experienced clinical care matters for cardiac surgery patients, a new study found.

The report, published in Critical Care Medicine, found that those patients treated around the clock by senior intensivists had a 7% lower risk of major complications, and an almost 4% lower risk of readmission to cardiac surgical ICU, compared to a similar group receiving care from resident physicians.

University of Alberta researchers report that patients with more experienced care also spend less time receiving mechanical ventilation and had fewer surgical postponements.

Included in the study were more than 3,000 patients at the University of Alberta Hospital and Mazankowski Alberta Heart Institute in Canada. While half were cared for at night by resident physicians over a seven-year period (2006-2013), the other half received treatment from in-house intensivist physicians over a period of 17 months during 2013 and 2014.

Of the patients monitored by residents, 26% of them had major complications, compared to 19% of those treated by the intensivists, and 5.3% had to be readmitted to the ICU, compared to 1.6% of those getting more experienced care.

"There have previously been large studies [examining this issue in general ICUs] and they have not found any benefit to taking residents away or adding staff physicians," explained study author Marc Benoit, MD, a fellow in cardiology at the University of Alberta. "But we thought the cardiac ICU here might be different because the patients are more complex. Someone with a heart transplant who is sick is different than a standard hospital patient."

"With more senior staff in-house at night, people were taken off the ventilators faster and we think there probably was more attention to detail for infection prevention. That is a possible explanation,” he added.

Study authors caution that their results are observational and do not take into account all other factors that could have affected outcomes.

"When looking at this issue of nighttime staffing, we need to consider the patient population. So maybe it's not beneficial to keep senior physicians in-house in every single ICU, but it might be in some more complex units," Benoit said. "It is worth thinking about. Staffing patterns and care models can have very important effects on patient outcomes."