Every July, U.S. hospitals take on new doctors-in-training and others are promoted. Some studies have found there are more medical errors and patient deaths around this time of year.
But for the most common heart procedure performed worldwide, a new study suggests there may not be a "July effect."
Percutaneous coronary intervention (PCI), also known as coronary angioplasty, opens blockages of the arteries that supply blood to the heart.
"These blockages can cause heart attacks or chest discomfort," said senior author Dr. Robert W. Yeh. "The procedure typically involves entering the body through arteries in the wrist or the groin and opening vessels in the heart with small balloons and metal scaffolds known as stents."
Yeh is from the cardiology division of Massachusetts General Hospital in Boston.
He and his team analyzed the results of PCIs performed at 136 hospitals affiliated with accredited interventional cardiology training programs between 2009 and 2012. They considered July and August early in the year and September through June late in the year.
There were more than 300,000 PCIs performed during the study period. The researchers found all complications related to the procedures - including excessive bleeding, vascular problems and deaths, heart attacks and strokes - were equally common in the early and late periods, they reported in the Journal of the American College of Cardiology.
The researchers couldn't say precisely how trainees were involved in the procedures at each hospital. But they did survey 81 of the program directors about how involved trainees generally are in PCI and found their level of involvement also didn't seem to influence patient health.
Yeh said he was somewhat surprised that there seemed to be no July effect.
"With a technically complex procedure like PCI, one might have expected some signal of increased complications or worse outcomes with less experienced physicians," he said.
Timing could still play a role for other procedures, Yeh said.
"Every procedure in every discipline is different, and the systems in place to ensure proper oversight likely differ as well," he said.
"In cardiology, perhaps more than any other field, so much attention has been placed on the measurement and transparent reporting of patient outcomes to assess true quality of care, and this emphasis probably translates to improved safety mechanisms to reduce the potential for a July effect."
Within training programs, trainees and experienced faculty perform PCI together throughout the year, Dr. Alice Jacobs, the director of the Cardiac Catheterization Laboratory and Interventional Cardiology at Boston Medical Center, which is an academic center, said. Earlier in the year, trainees may be the "primary operator," actually manipulating the catheter, less often, she said.
Jacobs was not involved in the new study.
The July effect may be less of an issue for PCI compared to other procedures in which faculty are not involved, she said.
It was relatively easy to compare PCI outcomes at different times of year since the procedures are so common, but for other procedures there is not enough data, Yeh said.
Many patients know summer is the time when new trainees come on board, he added.
"The fact that they bring it up in conversation makes me think there are more people worried about it than perhaps we suspect," he said.
For PCI, patients and doctors should take heart from these results that summer and winter outcomes don't seem to differ, he said.
"I think patients should schedule their procedures when they feel the most comfortable doing so," Yeh said. "This means looking at whether or not one can afford to potentially spend a few days in the hospital if necessary during that time, whether their preferred care team is available and whether they have support systems available then, among other things."