Electrocardiographic Criteria for ST-Elevation Myocardial Infarction in Patients With Left Ventricular Hypertrophy

Patients with electrocardiographic (ECG) left ventricular hypertrophy (LVH) have repolarization abnormalities of the ST segment that may be confused with an ischemic current of injury. We analyzed the ACTIVATE-SF database, a registry of consecutive emergency department ST-segment elevation (STE) myocardial infarction diagnoses from 2 medical centers. Univariate analysis was performed to identify ECG variables associated with presence of an angiographic culprit lesion. Recursive partitioning was then applied to identify a clinical decision-making rule that maximizes sensitivity and specificity for presence of an angiographic culprit lesion. Seventy-nine patients with ECG LVH underwent emergency cardiac catheterization for primary angioplasty. Patients with a culprit lesion had greater magnitude of STE (3.0 ± 1.8 vs 1.9 ± 1.0 mm, p = 0.005), more leads with STE (3.1 ± 1.6 vs 2.0 ± 1.8 leads, p = 0.002), and a greater ratio of STE to R-S-wave magnitude (median 25% vs 9.2%, p = 0.003). Univariate application of ECG criteria had limited sensitivity and a high false-positive rate for identifying patients with an angiographic culprit lesion. In patients with anterior territory STE, using a ratio of ST segment to R-S-wave magnitude ≥25% as a diagnostic criteria for STE myocardial infarction significantly improved specificity for an angiographic culprit lesion without decreasing sensitivity (c-statistic 0.82), with a net reclassification improvement of 37%. In conclusion, application of an ST segment to R-S-wave magnitude ≥25% rule may augment current criteria for determining which patients with ECG LVH should undergo primary angioplasty.     

Outcomes and Revascularization Strategies of ST-Elevation Myocardial Infarction in Patients With Hypertrophic Cardiomyopathy

Myocardial ischemia is a known complication of HCM. Contemporary outcomes and care processes after STEMI are extensively examined; however, there are limited data on outcomes, and revascularization strategies of HCM patients with STEMI. The National Inpatient Sample 2004-2018 was queried to identify adult patients presenting with a primary diagnosis of STEMI, of whom a subset of patients with concomitant diagnosis of HCM were identified. Complex samples multivariable logistic and linear regression models were used to determine the association of HCM with in-hospital outcomes. HCM patients with STEMI who were revascularized were compared with their counterparts who were not revascularized. Of 3,049,068 primary STEMI hospitalizations, 2583 (0.8%) had an associated diagnosis of HCM. HCM patients were more likely to be elderly and female with less traditional cardiovascular risk factors compared to those without HCM. HCM patients were less likely to receive revascularization compared to those without HCM. STEMI with HCM was associated with similar in-hospital mortality (adjusted odds ratio [aOR] 1.09; 95% confidence interval [CI] 0.82-1.44; P = 0.561) compared to those without HCM. Notably, HCM patients who were revascularized had similar in-hospital mortality (aOR 0.69; 95% CI 0.36-1.33; P = 0.266) compared to HCM patients who did not receive revascularization. Despite lower rates of revascularization, STEMI in patients with HCM is associated with similar in-hospital mortality compared to those without HCM.     

Tombstoning ST-Elevation Myocardial Infarction

Tombstoning ST elevation myocardial infarction can be described as a STEMI characterized by tombstoning ST-segment elevation. This myocardial infarction is associated with extensive myocardial damage, reduced left ventricle function, serious hospital complications and poor prognosis. Tombstoning ECG pattern is a notion beyond morphological difference and is associated with more serious clinical results.Despite the presence of a few reports on tombstoning ST elevation, there is no report which reviews STEMI demonstrating this electrocardiographic pattern.     

Reperfusion Times and Outcomes in Patients With ST-Elevation Myocardial Infarction Presenting Without Pre-Hospital Notification

BackgroundPrimary percutaneous coronary intervention (PCI) for patients with ST-elevation myocardial infarction (STEMI) is recommended within 90 min of first medical contact. Those without pre-hospital notification (PN) are less likely to meet reperfusion targets and are an understudied subset of the STEMI population.MethodsAn observational cohort study from a multicentre PCI registry of consecutive patients undergoing primary PCI for STEMI between 2012 and 2017. Exclusion criteria included out-of-hospital cardiac arrest, prior thrombolysis, symptom onset >12 h prior, and cardiogenic shock.Results2519 patients were included: 1392 (55.3%) without PN (no-PN group) and 1127 (44.7%) with PN (PN group). Those without PN had longer median DTBT (78 min vs 51 min, p < 0.001) and STBT (206 min vs 161 min, p < 0.001), with only 55% meeting DTBT targets out-of-hours in the no-PN group. No-PN patients had lower rates of AHA/ACC type B2/C lesions, GP IIb/IIIa use, aspiration thrombectomy and had smaller stent diameter (all p ≤ 0.003), suggesting smaller areas of ischemic myocardium. There were no significant differences in 30-day MACE (no-PN 5.6% vs PN 6.5%, p = 0.36) or long-term National Death Index linked mortality (no-PN 6.2% vs PN 7.9%, p = 0.09). Lack of PN did not independently predict long-term mortality.ConclusionDespite comparably excellent outcomes overall, those without PN had longer ischemic times and were less likely to meet DTBT targets, especially after hours. Ischemic times may be a better evaluation of PN networks than hard clinical outcomes, and efficient systems of care tailored to the individual health service are essential to ensure timely reperfusion of patients with STEMI.     

Acute Management of ST-Elevation Myocardial Infarction Patients Taking Dabigatran

The novel oral anticoagulant agents provide compelling evidence-based advance over warfarin therapy in nonvalvular atrial fibrillation and have received endorsement from contemporary guidelines. This case illustrates the challenge that clinicians will have to manage patients taking these agents who present with ST-elevation myocardial infarction requiring acute reperfusion therapy. We used a “logical” although not evidence-based approach to applying a pharmacoinvasive strategy that might be considered by others. Additionally we propose suggestions for urgent percutaneous coronary intervention while taking dabigatran, a strategy that should be implemented cautiously and adapted as further evidence becomes available.     

Procedural Variations in Performing Primary Percutaneous Coronary Intervention in Patients With ST-Elevation Myocardial Infarction

Multiple variations exist in performing a primary percutaneous coronary intervention (pPCI) in ST-segment elevation myocardial infarction (STEMI) among various cardiologists. These variations range from the choice of peripheral access artery (radial vs femoral), performance or time of complete angiography including left ventriculography, and nonculprit vessel angiography before or after intervening on the culprit vessel. The reasons for such variations include emphasis on door-to-balloon time, knowledge of cardiac anatomy before proceeding with pPCI, physician expertise, and the level of comfort with radial approach. Over the last 2 decades, the field of interventional cardiology has changed dynamically leading to marked improvements in the clinical outcomes of patients with STEMI. This includes upstreaming of pPCI along with technical advancements ranging from radial artery catheterization to culprit lesion–guided approach. Increased comfort with use of radial access approach by cardiologists and availability of multiuse guide catheters would both reduce door-to-balloon time and enable complete coronary angiography before performance of percutaneous coronary intervention. There are no clear guidelines or consensus dictating on cardiologists a correct sequence of action during STEMI, or even suggesting what the preferred approach is. Lack of guidelines results in a substantive variation in methodology. This review aims to highlight and to better understand the variations in the current practice, and to emphasize the advantages as well as the disadvantages of each approach. It is also perhaps a call out for guidelines that direct cardiologists to the best practice.     

Influence of Plaque Characteristics on Early Vascular Healing in Patients With ST-Elevation Myocardial Infarction

ObjectivesTo compare the early vascular healing of ruptured plaques (RP) and non-ruptured plaques (NRP) one month after primary percutaneous coronary intervention (PCI) in patients with ST-segment elevation myocardial infarction (STEMI), using optical coherence tomography (OCT).BackgroundVascular healing and strut coverage are important factors in reducing the risk of stent thrombosis after PCI. Influence of underlying lesion characteristics and differences in healing response between RP and NRP are unknown.MethodsTwenty-six STEMI-patients underwent PCI and implantation of a polymer-free drug-coated Biofreedom stent (BF-BES). OCT was performed pre-PCI, post-PCI and at 1-month follow-up. The patients were divided into two groups: RP = 15 and NRP = 11. OCT analyses of culprit lesion, post stent implantation at baseline and follow-up were performed to determine the difference in vascular healing based on presence of uncovered and/or malapposed stent struts and intraluminal filling defects.ResultsThe stent coverage did not differ significantly between the two groups at 1-month follow-up with percentage of uncovered struts: RP 26.5% [IQR 15.0–49.0] and NRP 28.1% [IQR 15.5–38.8] for NRP (p = 0.78). At 1-month, RP showed an increased percentage of late acquired malapposed struts (1.4% [IQR 0.8–2.4] vs. 0.0% [IQR 0.0–1.4], p = 0.03) and a larger total malapposition area (1.3 mm² [IQR 0.4–2.5] vs. 0.0 mm² [IQR 0.0–0.9], p = 0.01), compared to NRP.ConclusionThree out of four struts were covered within one month after stenting. The vascular healing was comparable in RP and NRP on stent coverage. However, RP had more and larger late acquired malapposition areas.     

Long-term Follow-up of Patients Undergoing Postconditioning During ST-Elevation Myocardial Infarction

Reperfusion injury may offset the optimal salvage of myocardium achieved during primary coronary angioplasty. Thus, coronary reperfusion must be combined with cardioprotective adjunctive therapies in order to optimize myocardial salvage and minimize infarct size. Forty-three patients with their first ST-elevation myocardial infarction were randomized to myocardial postconditioning or standard of care at the time of primary coronary angioplasty. Postconditioning was performed immediately upon crossing the lesion with the guide wire and consisted of four cycles of 30 s occlusion followed by 30 s of reperfusion. End-points included infarct size, myocardial perfusion grade (MPG), left-ventricular ejection fraction (LVEF), and long-term clinical events (death and heart failure). Despite similar ischemic times (≅4.5 h) (p = 0.9) a reduction in infarct size was observed among patients treated with the postconditioning protocol. Peak creatine phosphokinase (CPK), as well as its myocardial band (MB) fraction, was significantly lower in the postconditioning group when compared with the control group (CPK—control, 2,444 ± 1,928 IU/L vs. PC, 2,182 ± 1,717 IU/L; CPK-MB—control, 242 ± 40 IU/L vs. PC, 195 ± 33 IU/L; p = 0.64 and p < 0.01, respectively). EF in the postconditioning group was improved when compared with the control group (control, 43% ± 15 vs. PC, 52% ± 9; p = 0.05). After a mean follow-up of 3.4 years, a 6-point absolute difference in LVEF was still evident in the postconditioning group (p = 0.18). MPG was better among patients treated with the postconditioning protocol compared with control (2.5 ± 0.5 vs. 2.1 ± 0.6; p = 0.02). Due to the small sample size no significant differences in clinical events were detected (p value for death = 0.9; p value for heart failure = 0.2). A simple postconditioning protocol applied at the onset of mechanical reperfusion, resulted in reduction of infarct size, better epicardial and myocardial flow, and improvement in left ventricular function. The beneficial effects of postconditioning on cardiac function persist beyond 3 years.     

Acute Myocardial Infarction in Diabetic Patients

ABSTRACT. All patients hospitalized during a 3-year period with an acute myocardial infarction were followed for the occurrence of reinfarction or death. The patients with diabetes mellitus (n=95) were compared with the non-diabetic population (n=545). The diabetics had a higher mortality rate (relative death rate of 1.44 vs. 0.93, p<0.01) and a higher frequency of reinfarctions (18.9 vs. 10.8%, p=0.04) than the non-diabetic population. A larger proportion of the diabetics had suffered a previous infarction, but the excess mortality was also present in those without a previous infarction. Established risk factors for death after myocardial infarction, such as age, infarct size, infarct localization and heart size, could not account for the difference in mortality. It is suggested that the increased mortality among the diabetics may be due to an increase in the rate of progression of the atherosclerotic heart disease.     

Circulating MIF Levels Predict Clinical Outcomes in Patients With ST-Elevation Myocardial Infarction After Percutaneous Coronary Intervention

BackgroundThe purpose of the study was to assess the value of admission macrophage migration inhibitory factor (MIF) levels in predicting clinical outcomes in ST-elevation myocardial infarction (STEMI) patients.MethodsFor this study we recruited 498 STEMI patients after they received percutaneous coronary intervention (PCI), 40 with stable angina pectoris and 137 healthy participants. Plasma MIF levels were measured at admission and after PCI. The primary end points were in-hospital mortality and major adverse cardio-and/or cerebrovascular events (MACCE) during hospitalization and 3.2-year follow-up period.ResultsAdmission MIF levels were elevated in 88.4% of STEMI patients over the upper reference limit of healthy controls and it was 3- to 7-fold higher than that in stable angina pectoris and control groups (122 ± 61 vs 39 ± 19 vs 17 ± 8 ng/mL; P < 0.001). Admission MIF levels were significantly higher in patients who died after myocardial infarction vs survivors. For predicting in-hospital mortality using the optimal cutoff value (127.8 ng/mL) of MIF, the area under the receiver operating characteristic curve for MIF was 0.820, similar area under the receiver operating characteristic curve values for predicting short-term outcomes were observed for high-sensitivity troponin T, CK-MB, N-terminal probrain natriuretic peptide, and Global Registry of Acute Coronary Events (GRACE) score. Although peak high-sensitivity troponin T and N-terminal probrain natriuretic peptide also predicted MACCE during the follow-up period, only higher admission MIF levels predicted in-hospital mortality and MACCE during the 3.2-year follow-up. Multivariate regression analysis showed the independent predictive value of a higher admission MIF level (≥ 127.8 ng/mL) on in-hospital mortality (odds ratio, 9.1; 95% confidence interval, 1.7-47.2) and 3.2-year MACCE (hazard ratio, 2.8; 95% confidence interval, 1.5-5.6).ConclusionsA higher admission MIF level is an independent predictor for in-hospital mortality and long-term MACCE in STEMI patients who underwent PCI.     

Radial vs. Femoral Access for Percutaneous Coronary Artery Intervention in Patients With ST-Elevation Myocardial Infarction

BackgroundWe aimed to compare the safety and efficacy of transradial vs transfemoral access for coronary angiography and intervention in patients presenting with ST-segment elevation myocardial infarction (STEMI) without cardiogenic shock.MethodsPubMed, Embase and Cochrane Central were searched for randomized controlled trials (RCTs) comparing outcomes of STEMI patients who underwent transradial angiography (TRA) compared to transfemoral angiography (TFA). Our outcomes of interest were major adverse cardiac events (MACE), all-cause mortality, severe bleeding, access site bleeding, myocardial infarction, stroke, and major vascular complications. Summary statistics are reported as odds ratios (OR) with 95% confidence intervals (CI).ResultsIn a pooled analysis of 17 RCTs with 12,118 randomized patients, the use of transradial compared to transfemoral approach in STEMI patients without cardiogenic shock was associated with a significant reduction in MACE [OR 0.85 (95% CI 0.73–0.99; p = 0.04; NNT = 111; I² = 0%)] and all-cause mortality [OR 0.71 (95% CI 0.57–0.88; p < 0.01; NNT = 111; I² = 0%)]. Severe bleeding [OR 0.57 (95% CI 0.44–0.74; p < 0.01; NNT = 77; I² = 0%)], access-site bleeding [OR 0.39 (95% CI 0.26–0.59; p < 0.01; NNT = 67; I² = 24%)], and major vascular complications [OR of 0.31 (95% CI 0.17–0.55; p < 0.01; NNT = 125; I² = 0%)] were lower in TRA compared to TFA. There was no difference in stroke (0.6% vs 0.5%) or recurrent myocardial infarction (2.01% vs 2.02%) between the two approaches.ConclusionsFor coronary intervention in STEMI patients without cardiogenic shock, there is a clear mortality benefit with the TRA over TFA. Further studies are needed to see if this mortality benefit persists over the long-term.