Key messages
- We do not know if treating the coronary arteries (blood vessels of the heart) prior to major vascular surgery (surgery to the blood vessels) has an effect on preventing acute myocardial infarction (heart attack) and death (mortality) during surgery. Acute myocardial infarction may be reduced in the long term, but the evidence is very uncertain, and length of hospital stay may be reduced slightly.
- In order to determine the effect of treating the coronary arteries for preventing acute myocardial infarction in people undergoing major vascular surgery, more high‐quality studies are needed.
- Adverse effects (harms) associated with the treatments under study were poorly reported.
What is postoperative myocardial infarction?
Heart attacks are an important complication after surgery (postoperative myocardial infarction). This complication plays a large role in major vascular surgeries. Postoperative myocardial infarction is the leading cause of morbidity (illness) and mortality (death) after major vascular surgeries. Coronary artery disease is a condition that affects the blood vessels of the heart (coronary arteries) and occurs when these vessels are narrowed by a plaque (atherosclerosis), usually made of cholesterol. This disease is the main cause of myocardial infarction (when the narrowing progresses to a blockage of the vessel). Atherosclerosis could explain the association between postoperative myocardial infarction and major vascular surgery, as it is the most common cause of both diseases.
What did we want to find out?
We wanted to find out whether treating the coronary arteries prior to major vascular surgery (preoperative coronary interventions) can prevent postoperative myocardial infarction. Treatments to the coronary arteries consist of placing a catheter (thin tube) into an artery, usually in the leg or arm (percutaneous coronary intervention) and inserting it until it reaches the heart where a dye is injected to see if there is a narrowing of the coronary arteries (coronary angiography). Then, if a narrowing is identified, stents are used to open the blood vessels again bringing back the blood flow (coronary revascularisation). Another option for coronary revascularisation is coronary artery bypass graft (a surgical procedure used to bypass blockages in the coronary arteries). We wanted to know if identifying and treating people with severe coronary artery disease before vascular surgery decreases the number of heart attacks after vascular surgery.
What did we do?
We searched for trials that compared one group that received coronary treatments before major vascular surgery plus standard preoperative care (medical management or usual care) versus another group that received standard preoperative care (medical management or usual care) without coronary interventions. We wanted to know if there was a difference between groups in rates of heart attacks, mortality, or adverse outcomes. We compared these outcomes among trials and summarised our findings and then looked at whether the evidence was less or more reliable.
What did we find?
We found three trials involving 1144 participants. The trials compared either coronary angiography or coronary revascularisation, or both, before vascular surgery plus usual care to usual care alone (e.g. statins, angiotensin-converting enzyme inhibitors, and antiplatelet agents). The studies used different criteria to select their participants, for example including only those at high risk for coronary artery disease, or also including individuals at low risk. We were not able to combine data from one trial in our summary because a large number of participants in the usual care group also underwent coronary treatments.
We found that treating the coronary arteries before vascular surgery may decrease the long-term rate of heart attacks, but we are very uncertain about the results. Further, they may reduce length of hospital stay slightly in the short term compared to usual care alone. We did not find any difference between groups in short- and long-term mortality and in short-term heart attack rate. None of the trials reported all the outcomes that we were interested in. Adverse events were poorly reported in trials: one study reported no deaths due to coronary angiography, whereas the other two studies reported five deaths due to coronary revascularisation.
What are the limitations of the evidence?
We have little confidence in the results because participants and researchers were aware of which groups participants had been assigned to, which could have influenced the results. In addition, trials used different criteria to select their participants and used different methods, making it difficult to compare results. Finally, the overall results included the likelihood of having both benefit or harm from treatment to the coronary arteries before vascular surgery. None of the analysed trials provided information on subgroups of patients who could potentially experience greater benefits from the treatments under study, such as those with altered ventricular ejection fraction (ability of the heart to pump blood).
How up-to-date is the evidence?
The evidence is current to 13 March 2023.
Preoperative coronary interventions plus usual care may have little or no effect on preventing perioperative acute myocardial infarction and reducing perioperative all-cause mortality compared to usual care, but the evidence is very uncertain. Similarly, limited, very low-certainty evidence shows that preoperative coronary interventions may have little or no effect on reducing long-term all-cause mortality. There is very low-certainty evidence that preoperative coronary interventions plus usual care may prevent long-term myocardial infarction, and low-certainty evidence that they may reduce length of hospital stay slightly, but not cardiovascular mortality in the short term, when compared to usual care alone. Adverse effects of preoperative coronary interventions were poorly reported in trials. Quality of life and vessel or graft patency were not reported. We downgraded the certainty of the evidence most frequently for high risk of bias, inconsistency, or imprecision. None of the analysed trials provided significant data on subgroups of patients who could potentially experience more substantial benefits from preoperative coronary intervention (e.g. altered ventricular ejection fraction). There is a need for evidence from larger and homogeneous RCTs to provide adequate statistical power to assess the role of preoperative coronary interventions for preventing acute myocardial infarction in the perioperative period of major open vascular or endovascular surgery.
Postoperative myocardial infarction (POMI) is associated with major surgeries and remains the leading cause of mortality and morbidity in people undergoing vascular surgery, with an incidence rate ranging from 5% to 20%. Preoperative coronary interventions, such as coronary artery bypass grafting (CABG) or percutaneous coronary interventions (PCI), may help prevent acute myocardial infarction in the perioperative period of major vascular surgery when used in addition to routine perioperative drugs (e.g. statins, angiotensin-converting enzyme inhibitors, and antiplatelet agents), CABG by creating new blood circulation routes that bypass the blockages in the coronary vessels, and PCI by opening up blocked blood vessels. There is currently uncertainty around the benefits and harms of preoperative coronary interventions.
To assess the effects of preoperative coronary interventions for preventing acute myocardial infarction in the perioperative period of major open vascular or endovascular surgery.
We searched the Cochrane Vascular Specialised Register, CENTRAL, MEDLINE Ovid, Embase Ovid, LILACS, and CINAHL EBSCO on 13 March 2023. We also searched the World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov.
We included all randomised controlled trials (RCTs) or quasi-RCTs that compared the use of preoperative coronary interventions plus usual care versus usual care for preventing acute myocardial infarction during major open vascular or endovascular surgery. We included participants of any sex or any age undergoing major open vascular surgery, major endovascular surgery, or hybrid vascular surgery.
We used standard Cochrane methods. Our primary outcomes of interest were acute myocardial infarction, all-cause mortality, and adverse events resulting from preoperative coronary interventions. Our secondary outcomes were cardiovascular mortality, quality of life, vessel or graft secondary patency, and length of hospital stay. We reported perioperative and long-term outcomes (more than 30 days after intervention). We assessed the certainty of the evidence using the GRADE approach.
We included three RCTs (1144 participants). Participants were randomised to receive either preoperative coronary revascularisation with PCI or CABG plus usual care or only usual care before major vascular surgery. One trial enrolled participants if they had no apparent evidence of coronary artery disease. Another trial selected participants classified as high risk for coronary disease through preoperative clinical and laboratorial testing. We excluded one trial from the meta-analysis because participants from both the control and the intervention groups were eligible to undergo preoperative coronary revascularisation. We identified a high risk of performance bias in all included trials, with one trial displaying a high risk of other bias. However, the risk of bias was either low or unclear in other domains.
We observed no difference between groups for perioperative acute myocardial infarction, but the evidence is very uncertain (risk ratio (RR) 0.28, 95% confidence interval (CI) 0.02 to 4.57; 2 trials, 888 participants; very low‐certainty evidence). One trial showed a reduction in incidence of long-term (> 30 days) acute myocardial infarction in participants allocated to the preoperative coronary interventions plus usual care group, but the evidence was very uncertain (RR 0.09, 95% CI 0.03 to 0.28; 1 trial, 426 participants; very low‐certainty evidence). There was little to no effect on all-cause mortality in the perioperative period when comparing the preoperative coronary intervention plus usual care group to usual care alone, but the evidence is very uncertain (RR 0.79, 95% CI 0.31 to 2.04; 2 trials, 888 participants; very low‐certainty evidence). The evidence is very uncertain about the effect of preoperative coronary interventions on long-term (follow up: 2.7 to 6.2 years) all-cause mortality (RR 0.74, 95% CI 0.30 to 1.80; 2 trials, 888 participants; very low‐certainty evidence). One study reported no adverse effects related to coronary angiography, whereas the other two studies reported five deaths due to revascularisations. There may be no effect on cardiovascular mortality when comparing preoperative coronary revascularisation plus usual care to usual care in the short term (RR 0.07, 95% CI 0.00 to 1.32; 1 trial, 426 participants; low-certainty evidence). Preoperative coronary interventions plus usual care in the short term may reduce length of hospital stay slightly when compared to usual care alone (mean difference −1.17 days, 95% CI −2.05 to −0.28; 1 trial, 462 participants; low‐certainty evidence).
We downgraded the certainty of the evidence due to concerns about risk of bias, imprecision, and inconsistency. None of the included trials reported on quality of life or vessel graft patency at either time point, and no study reported on adverse effects, cardiovascular mortality, or length of hospital stay at long-term follow-up.