LONDON – Statin therapy, given the week before a host of noncardiac surgical procedures, reduced the postoperative risk for death and cardiac complications at 30 days by 17% when compared with no statin use in a large, international observational study.
Results of the prospective VISION (Vascular Events in Noncardiac Surgery Patients Cohort Evaluation) study showed that the primary composite endpoint of all-cause mortality, myocardial injury after noncardiac surgery (MINS), or stroke at 30 days was 11.8% in a propensity-matched cohort of patients, 2,845 of whom were treated with a statin and 4,492 who were not. The relative risk (RR) for this composite endpoint was 0.83 favoring the use of preoperative statins, with a 95% confidence interval (CI) of 0.73-0.95 and a P value of .007.
Sara Freeman/Frontline Medical News
Dr. Otavio Berwanger
Perioperative statin vs. no statin use also cut all-cause mortality by 42% (RR, 0.58; 95% CI, 0.40-0.83; P = .003), cardiovascular mortality by 58% (RR, 0.42; 95% CI, 0.23-0.76; P = .004), and MINS by 14% (RR, 0.86; 95% CI, 0.73-0.98; P = .002).
“These study results are hypothesis generating at most,” emphasized Dr. Otavio Berwanger, who presented the findings at the annual congress of the European Society of Cardiology while they were simultaneously published online (Eur Heart J. 2015 Sept. 1. doi: 10.1093/eurheartj/ehv456).
“It is true that, in this large representative cohort of contemporary patients, statins were associated with lower event rates,” added Dr. Berwanger of Hospital do Coração in São Paulo, Brazil, and “together with the previous body of evidence, statins appear to be an interesting and attractive intervention to reduce postoperative events.” A large-scale, randomized trial is needed, however, to answer the question of whether statins should be used preoperatively to prevent postoperative events in noncardiac surgery patients.
Over a 4-year period that started in August 2007, more than 15,000 individuals aged 45 years or older who were undergoing a variety of noncardiac surgical procedures that required regional or a general anesthetic and at least an overnight stay in the hospital were recruited at 12 centers in eight countries in North and South America, Africa, Asia, Australia, and Europe.
One of the objectives of the study was to examine the use of perioperative statins on cardiovascular events at 30 days, and to do this, the VISION investigators identified the patients who had received a statin in the 7 days prior to surgery and then used propensity matching to form a control group of patients that had not received a statin in the week before surgery.
Just under half of the propensity-matched population was male, with an average age of nearly 69 years. Around 70% of the population had hypertension, 9%-10% had a prior stroke, and 13% had active cancer. Surgeries were urgent in about 2% and emergent in 8%. Around a quarter had undergone orthopedic procedures, and 4% were vascular surgeries. Overall, 36% of surgeries were classified as low risk and 39% as other.
One of the limitations of the study, however, is that, despite the propensity matching, there were some variables that remained different between the two groups, with higher rates of coronary artery disease (20% vs. 14%), peripheral vascular disease (8% vs. 5%), diabetes (30% vs. 25%), and preoperative use of aspirin (25% vs. 19%) and angiotensin-converting enzyme inhibitors or angiotensin receptor blockers (53% vs. 48%) in the statin- versus nonstatin-treated patients.
Other limitations are that these data are observational and the use of statins could be just a surrogate for unmeasured confounders that relate to prognosis. Information on the type and dosing of statins also was not obtained, and there was no information collected on potential liver or muscle function side effects.
Nevertheless, the VISION investigators noted in the published paper that the results are consistent with those from other observational studies and prior small-scale, randomized trials and so do add important information. They noted that these data were collected prospectively in a broader range of patients and types of surgeries than has been reported previously. In addition, patients were recruited from several countries and were actively monitored for outcomes and events were centrally adjudicated. VISION is also the only study to report on the effects of statins on MINS.
“Another message from our results is that the use of long-term statins is sub-optimal in high cardiovascular risk patients, who should be on long-term lipid-lowering therapy independently of surgery,” the VISION investigators wrote in their report.
The study was funded by Hamilton Health Sciences Corp. at McMaster University. Dr. Berwanger disclosed receiving research contracts from AstraZeneca, Bayer Healthcare, Amgen, Boehringer-Ingelheim, Pfizer, and Roche Diagnostics.