Physician's Weekly Article - Preventing Adverse Cardiac Events in Surgery

       Adverse cardiac events in major surgeries continue to plague hospitals, but efforts are being made to develop evidence-based tools that help prevent these complications.

      The Surgical Care Improvement Project—Series #2

      This Physician’s Weekly feature story is the second of a three-part series on the Surgical Care Improvement Project. The first part of this series described tools to manage surgical site infections. The series will conclude with a feature that evaluates tools to help surgeons prevent and treat deep vein thrombosis in surgical patients.

      The national network of Quality Improvement Organizations (QIOs) provides technical assistance to hospitals taking part in the Surgical Care Improvement Project (SCIP), a program launched by a broad group of organizations aimed at reducing often preventable complications that endanger surgical patients. The primary goal of the SCIP partnership is to reduce the incidence of surgical complications by 25% by 2010 throughout the nation. SCIP partners commit to promoting care processes known to reduce surgical complications, and the QIO network is the primary education and training channel for the effort.

      One of the key SCIP initiatives is to prevent perioperative cardiac events that can result from surgery; these events are significant complications (Table 1). “Adverse cardiac events are associated with prolonged hospitalization, which in turn can increase costs substantially,” says Lee A. Fleisher, MD. “In fact, we have data which demonstrates that the increase in resource utilization associated with perioperative myocardial ischemic injury result in estimated incremental cost per patient is $9,980. In open vascular procedures alone, that total burden approximates $440 million.”

      β-Blockers Play an Important Role

      In 2006, Dr. Fleisher chaired a task force convened by the American Heart Association and American College of Cardiology (AHA/ACC) that released recommendations on managing perioperative cardiovascular events in non-cardiac surgery, focusing heavily on the importance of β-blockers during and after operations (Table 2). Current studies suggest that β-blockers reduce perioperative ischemia and may reduce the risk of MI and death in selected high-risk patients.

      Considering the AHA/ACC guidelines and other mounting evidence surrounding the impact of β-blockers, the SCIP initiative has set a quality measure for patients currently on β-blocker therapy at the time of surgery to continue that therapy both before and after their operation. According to data from SCIP, some studies have suggested that nearly half of all fatal perioperative cardiac events could be prevented with appropriate β-blocker therapy.

      Although many of the randomized, controlled trials reported in the AHA/ACC guidelines assessing β-blocker therapy are small, Dr. Fleisher says the weight of evidence suggests a benefit to perioperative β blockade during non-cardiac surgery in those currently taking these agents and in selected high-risk vascular surgery patients. “Evidence suggests—but does not definitively prove—that β-blockers should be started several days or weeks before elective surgery. The dose should also be titrated to achieve a resting heart rate between 50 and 60 beats per minute to assure that the patient is indeed receiving the benefit of β blockade. The therapy should also be continued during the intraoperative and postoperative periods to maintain a heart rate less than 80 beats per minute.”

      Although SCIP only measures Class I recommendations, Dr. Fleisher says there are patients who should be taking β-blockers for long-term benefits, but are not on the agents at the time of surgery. There is currently no evidence to demonstrate that acute administration in the perioperative period will impact outcome. “For this reason,” Dr. Fleisher says, “we considered administration of β blockade as a Class IIa indication in the new guidelines, suggesting that their administration will likely be beneficial, but that this indication lacks evidence to mandate inclusion as a quality of care measure. These indications may be excellent quality improvement initiatives at a local hospital in which they should continue to monitor whether or not these practices will actually lead to improved outcomes, both short and long term.”

      More Research is Warranted

      Several prospective, randomized trials are emerging that will hopefully shed more light on some of the questions regarding perioperative β-blocker therapy, Dr. Fleisher adds. “The strongest evidence for perioperative β blockade comes from prospective randomized trials, but while several small randomized trials demonstrated a strong beneficial effect, others did not. We need more studies in the future that aim to determine the ideal target population, ideal dose, and route. Additionally, there are practical limitations to consider, including how, when, how long, and by whom perioperative β-blocker therapy is ideally or practically implemented. Furthermore, investigations are needed to explore observations suggesting that there may be some harm associated with β-blocker therapy in low-risk patients. Generally speaking, the best approach on how to medically protect patients from cardiovascular complications during non-cardiac surgery is still unknown.”

      Dr. Fleisher has indicated to Physician’s Weekly that he has or has had no financial interests to report.