Effects of Metoprolol on Periprocedural Myocardial Infarction After Percutaneous Coronary Intervention (Type 4a MI): An Inverse Probability of Treatment Weighting Analysis

Background: Metoprolol is the most used cardiac selective β-blocker and has been recommended as a mainstay drug in the management of acute myocardial infarction (AMI). However, the evidence supporting this regimen in periprocedural myocardial infarction (PMI) is limited.Methods: This study identified 860 individuals who suffered PMI following percutaneous coronary intervention (PCI) procedure and median followed up for 3.2 years. Subjects were dichotomized according to whether they received chronic oral sustained-release metoprolol succinate following PMI. After inverse probability of treatment weighting (IPTW) adjustment, logistic regression analysis, Kaplan-Meier curve, and Cox regression analysis were performed to estimate the effects of metoprolol on major adverse cardiovascular events (MACEs) which composed of cardiac death, myocardial infarction (MI), stroke, and revascularization. Moreover, an exploratory analysis was performed according to hypertension, cardiac troponin I (cTnI) elevation, and cardiac function. A double robust adjustment was used for sensitivity analysis.Results: Among enrolled PMI subjects, 456 (53%) patients received metoprolol treatment and 404 (47%) patients received observation. After IPTW adjustment, receiving metoprolol was found to reduce the subsequent 3-year risk of MACEs by nearly 7.1% [15 vs. 22.1%, absolute risk difference (ARD) = 0.07, number needed to treat (NNT) = 14, relative risk (RR) = 0.682]. In IPTW-adjusted Cox regression analyses, receiving metoprolol was related to a reduced risk of MACEs (hazard ratio [HR] = 0.588, 95%CI [0.385–0.898], P = 0.014) and revascularization (HR = 0.538, 95%CI [0.326–0.89], P = 0.016). Additionally, IPTW-adjusted logistic regression analysis showed that receiving metoprolol reduced the risk of MI at the third year (odds ratio [OR] = 0.972, 95% CI [0.948–997], P = 0.029). Exploratory analysis showed that the protective effect of metoprolol was more pronounced in subgroups of hypertension and cTnI elevation ≥1,000%, and was remained in patients without cardiac dysfunction. The benefits above were consistent when double robust adjustments were performed.Conclusion: In the real-world setting, receiving metoprolol treatment following PCI-related PMI has decreased the subsequent risk of MACEs, particularly the risk of recurrent MI and revascularization.

Impact of Periprocedural Myocardial Injury and Infarction Definitions on Long-Term Mortality After Chronic Total Occlusion Percutaneous Coronary Intervention

Background: The prognostic implications of biomarker elevation following percutaneous coronary intervention (PCI) of chronic total occlusion (CTO) lesions remain controversial. This study assessed the association of periprocedural myocardial injury and clinically relevant definition of periprocedural myocardial infarction with subsequent outcomes after CTO-PCI. Methods: We enrolled consecutive patients between January 2010 and December 2013 who underwent CTO-PCI at a large-volume center with serial CK-MB (creatine kinase–myocardial band) or cTnI (cardiac troponin I) measurements. The primary outcome was 5-year cardiovascular death. Results: A total of 2616 patients (2691 CTOs) with postprocedural CK-MB or cTnI undergoing PCI recanalization were included, per-lesion technical success rate was 74.4%. Postprocedural CK-MB and cTnI elevation occurred in 5.6% and 65.5% patients, respectively. For 2485 patients with serial CK-MB measurements, only postprocedural peak CK-MB ≥5× upper reference limit was associated with increased 5-year cardiovascular death (adjusted hazard ratio, 9.88 [95% CI, 3.06–31.9]). In contrast, for 1233 patients with serial cTnI measurements, no such association was present in any threshold. The Society for Cardiovascular Angiography and Interventions definition of periprocedural myocardial infarction was associated with 5-year cardiovascular death (adjusted hazard ratio, 8.45 [95% CI, 3.58–20.0]), whereas the ARC-2 (Academic Research Consortium-2) and fourth UDMI (Universal Definition of Myocardial Infarction) were not. Conclusions: In a large cohort of CTO-PCI, moderate to high levels of peak postprocedural CK-MB were prognostically significant, whereas such association was not observed in postprocedural cTnI. The Society for Cardiovascular Angiography and Intervention criteria (but not ARC-2 and fourth UDMI) were identified as clinically relevant periprocedural myocardial infarction definition following CTO-PCI.

Incidence and one year outcome of periprocedural myocardial infarction following cardiac surgery: are the universal definition and SCAI criteria fit for purpose?

Introduction The diagnosis and clinical implication of periprocedural myocardial infarction (PPMI) following coronary artery bypass grafting (CABG) is contentious, especially given its importance in the interpretation of trial data. Two accepted definitions of PPMI yield discrepant results. Little is known about the association between the diagnosis of PPMI, using high sensitivity troponin (hs-cTn), and medium term mortality in patients who undergo CABG, either alone or in conjunction with another procedure. In addition, there are currently no criteria for the diagnosis of PPMI following non-CABG surgery. Method Consecutive patients admitted to a cardiothoracic critical care unit (CCCU) over a six month period following open cardiac surgery had hs-cTnI assay performed on admission and every day for forty-eight hours, regardless of whether there was a clinical indication. Patients were categorised as PPMI using both the Universal Definition of MI (UDMI) and Society of Cardiovascular Angiography and Interventions (SCAI) criteria. Comorbidity data, surgical details and clinical progress in CCCU were recorded. One year mortality data were obtained from NHS Digital. Results There were 245 CABG patients, of whom 20.4% met criteria for UDMI PPMI and 87.6% for SCAI UDMI (figure 1). The diagnosis of UDMI PPMI was independently associated with one year mortality (hazard ratio 4.175 (95% confidence interval 1.281 – 13.608)), whereas there was no association between SCAI PPMI and one year mortality (figure 2). Of the 243 patients who had non CABG cardiac surgery, 11.4% met criteria for UDMI PPMI and 85.2% for SCAI PPMI (figure1) but neither was associated with one year mortality. Conclusions The incidence of SCAI PPMI in a real world cohort of cardiac surgery patients is so high as to be of limited clinical value. By contrast, a diagnosis of UDMI PPMI post CABG is independently associated with one year mortality, so may have clinical utility. FUNDunding Acknowledgement Type of funding sources: Private company. Main funding source(s): Beckman Coulter - supplied the assays used in the study but had no role in the study Figure 1. Frequency of PPMI Figure 2. Kaplan Meier curves