Asymptomatic Perioperative Myocardial Injury Affects Vascular Outcomes

Main Category: Cardiovascular / Cardiology
Also Included In: Vascular;  Clinical Trials / Drug Trials
Article Date: 13 Jun 2009 - 3:00 PDT

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A new study reports that 75 percent of cardiac damage after vascular surgery is asymptomatic or patients' symptoms are concealed by postoperative complaints such as nausea and incision pain. This damage is associated with an increased risk for mortality. Researchers have found that screening for cardiac damage following surgery helps identify high-risk patients who might benefit from more aggressive medical therapy and follow-up after discharge. These findings are from a study presented today at the 63rd Annual Meeting of the Society for Vascular Surgery®.

"While the prognosis of symptomatic cardiac damage is known to be poor compared to patients without cardiac damage, the impact of asymptomatic cardiac damage is largely unknown," said Olaf Schouten, MD, Erasmus Medical Center of Rotterdam, The Netherlands. "Therefore, this study was performed to assess the long-term prognosis of vascular surgery patients who experience asymptomatic cardiac damage in the first week after major vascular surgery."

Dr. Schouten explained that appropriate screening consists of repeated measurement of cardiac troponin T (cTnT), a simple and sensitive laboratory marker for myocardial injury and cardiac damage after surgery. "However," he added, "the prognosis of cTnT elevations without clinical symptoms and/or new electrocardiographic changes (asymptomatic cTnT release) is unknown."

Initially 1,545 patients undergoing elective major vascular surgery were enrolled and baseline characteristics and medication were noted. Before surgery all patients were screened for the presence of cardiac risk factors such as a history of myocardial infarction, diabetes mellitus, and heart failure.

Routine sampling of cTnT and ECG recording was performed on days one, three, and seven after surgery and at the day of discharge. Elevated cTnT was defined as serum concentrations equal to or more than 0.01 ng/ml. Following surgery, cardiac damage occurred in 213 (14 percent) asymptomatic patients and in 71 (5 percent) symptomatic patients.

Patients were followed for a mean of 3.7 years after surgery. Asymptomatic cardiac damage in the perioperative period was associated with a poor long-term outcome compared to patients without cardiac damage. A total of 13 percent of patients without cardiac damage died during follow-up versus 40 percent of patients with asymptomatic cardiac damage. Also, after adjustment for risk factors and type and site of surgery asymptomatic cardiac damage was associated with a 2.3-fold increased risk for mortality during the first four years after vascular surgery, (adjusted HR 2.3; 95 percent; CI 1.8-3.0) and risk increased with higher cTnT levels (HR 1.64 for every 0.10 ng/ml increase, p=0.02). Elevated cTnT had prognostic value irrespective of baseline creatinine value or renal dysfunction after surgery.

"Asymptomatic cTnT release, without clinical symptoms or new ECG changes, is associated with an increased long-term mortality in patients undergoing vascular surgery," said Dr. Schouten. "Patients undergoing major arterial vascular surgery because of atherosclerotic disease are at high-risk for cardiac complications in the perioperative period. It is estimated that one out of five patients undergoing major vascular surgery suffers cardiac damage around the time of the operation if patients are appropriately screened in the first week after surgery. Screening is a valuable tool to determine how aggressive medical therapy should be for their long-term prognosis."

About the Society for Vascular Surgery®

The Society for Vascular Surgery (SVS) is a not-for-profit society that seeks to advance excellence and innovation in vascular health through education, advocacy, research and public awareness. SVS is the national advocate for 2,800 vascular surgeons dedicated to the prevention and cure of vascular disease

Source: Society for Vascular Surgery