Acute coronary angiography after coronary artery bypass grafting

Considerations on the Management of Acute Postoperative Ischemia After Cardiac Surgery: A Scientific Statement From the American Heart Association

Acute postoperative myocardial ischemia (PMI) after cardiac surgery is an infrequent event that can evolve rapidly and become a potentially life-threatening complication. Multiple factors are associated with acute PMI after cardiac surgery and may vary by the type of surgical procedure performed. Although the criteria defining nonprocedural myocardial ischemia are well established, there are no universally accepted criteria for the diagnosis of acute PMI. In addition, current evidence on the management of acute PMI after cardiac surgery is sparse and generally of low methodological quality. Once acute PMI is suspected, prompt diagnosis and treatment are imperative, and options range from conservative strategies to percutaneous coronary intervention and redo coronary artery bypass grafting. In this document, a multidisciplinary group including experts in cardiac surgery, cardiology, anesthesiology, and postoperative care summarizes the existing evidence on diagnosis and treatment of acute PMI and provides clinical guidance.

[Peculiariities of diagnostic parameters in patients with acute myocardial lesion after coronary artery bypass grafting]

Annually, up to 850 000 coronary aortic bypass graft operations are performed worldwide. Despite modern technical equipment ensuring a high level of safety of the procedure, currently important remains a problem related to intraoperative myocardial damage in using artificial circulation. Early detection and clinical assessment of myocardial ischaemia often present a difficult task. This article deals with clinical, instrumental and laboratory methods of diagnosis, aimed at verification of an intraoperative cardiac lesion associated with graft dysfunction in coronary artery bypass grafting. Isolated electrocardiographic and echocardiographic signs of myocardial ischaemia between the comparison groups did not differ significantly. Analysing the markers of myocardial lesions, statistically significant differences were obtained only after 48 hours which, from the point of view of saving viable myocardium, is an utterly long-term interval. Studying the findings of intraoperative flowmetry showed statistically significant dependence between velocity characteristics, pulse index of shunts and their patency on angiographic examination. Thus, only combination of diagnostic parameters makes it possible to detect myocardial damage related to shunt dysfunction. This enables early determination of indications for performing bypass angiography and selection of the required therapeutic policy. Timely coronary artery angiography makes it possible to reveal defects of shunts and to timely perform surgical correction, preventing myocardial infarction.

The Future of Cardioprotection-Pointing Toward Patients at Elevated Risk as the Target Populations

Translation of the cardioprotective effect by pharmacological and mechanical conditioning therapies into improvement of clinical outcome for the patients has been disappointing. Confounding factors like comorbidity and comedications may explain some of the loss in translation. However, the substantial improvement of outcome in disease states involving ischemia-reperfusion injury, that is, planned cardiac surgery, elective percutaneous coronary intervention, and even primary percutaneous coronary intervention for ST-segment myocardial infarction (STEMI), is the most plausible explanation for the missed demonstration of a clinical benefit. Remote ischemic conditioning has demonstrated consistent cardioprotective effect in experimental and in clinical proof-of-concept studies. As an adjunctive cardioprotective treatment beyond reperfusion, remote ischemic conditioning should address target populations at risk of extensive tissue damage, including patients who experience complications, which may induce profound myocardial ischemia in relation to cardiac surgery or elective percutaneous coronary intervention. Moreover, patients with STEMI and predictable impaired clinical outcome due to delayed hospital admission, high Killip class, cardiogenic shock, and cardiac arrest remain target groups. For high-risk patients, daily remote ischemic conditioning or the corollary of blood flow-restricted exercise may be alternative cardioprotective options during postoperative and post-myocardial infarct rehabilitation.

Control angiography for perioperative myocardial Ischemia after coronary surgery: meta-analysis

BACKGROUND

Perioperative myocardial ischemia (PMI) in patients undergoing coronary artery bypass grafting (CABG) is associated with poor outcome. The aim of this study was to pool the available data on the outcome after control angiography and repeat revascularization in patients with perioperative myocardial ischemia (PMI) after coronary artery bypass grafting (CABG).

METHODS

A literature review was performed through PubMed, Scopus, ScienceDirect and Google Scholar to identify studies published since 1990 evaluating the outcome of PMI after CABG.

RESULTS

Nine studies included 1104 patients with PMI after CABG and 1056 of them underwent control angiography early after CABG. Pooled early mortality after reoperation for PMI without control angiography was 43.6% (95%CI 29.7-57.6%) and 79.8% of them (95%CI 64.4-95.2%) had an acute graft failure detected at reoperation. Among patients who underwent control angiography for PMI, 31.7% had a negative finding at angiography (95%CI 25.6-37.8%) and 62.1% had an acute graft failure (95%CI 56.6-67.6%). Repeat revascularization was performed after early control angiography in 46.3% of patients (95%CI 39.9-52.6%; 54.2% underwent repeat surgical revascularization; 45.8% underwent percutaneous coronary intervention). Pooled early mortality after control angiography with or without repeat revascularization was 8.9% (95%CI 6.7-11.1%). Three studies reported on early mortality rates which did not differ between repeat surgical revascularization and PCI (11.7% vs. 9.2%, respectively; risk ratio 1.45, 95%CI 0.67-3.11). In these three series, early mortality after conservative treatment was 5.9% (95%CI 3.6-8.2%).

CONCLUSIONS

Control angiography seems to be a valid life-saving strategy to guide repeat revascularization in hemodynamically stable patients suffering PMI after CABG.