Mortality in ST-Segment Elevation Myocardial Infarction With Nonobstructive Coronary Arteries and Mimickers.

Importance: The clinical characteristics and prognosis of patients with ST-segment elevation myocardial infarction (STEMI) with nonobstructive coronaries (MINOCA) are largely unknown. Objective: To assess differences in 5-year mortality in patients presenting with STEMI due to MINOCA and MINOCA mimickers as compared with obstructive disease. Design, Setting, and Participants: A retrospective analysis of a prospective registry-based cohort study of consecutive STEMI activations at 3 regional Midwest STEMI programs. STEMI without a culprit artery and elevated troponin levels were categorized as MINOCA (absence of coronary artery stenosis >50% and confirmed or suspected coronary artery plaque disruption, epicardial coronary spasm, or coronary embolism/thrombosis) or MINOCA mimickers (takotsubo cardiomyopathy, myocarditis, or nonischemic cardiomyopathy). Data were analyzed from March 2003 to December 2020. Main Outcomes and Measures: Adjusted Cox regression analysis was used to assess 5-year mortality risk in STEMI presenting with MINOCA and MINOCA mimickers in comparison with obstructive disease. Results: Among 8560 consecutive patients with STEMI, mean (SD) age was 62 (14) years, 30% were female (2609 participants), and 94% were non-Hispanic White (4358 participants). The cohort included 8151 patients with STEMI due to obstructive disease (95.2%), 120 patients with MINOCA (1.4%), and 289 patients with MINOCA mimickers (3.8%). Patients were followed up for a median (IQR) of 7.1 (3.6-10.7) years. Patients with MINOCA and MINOCA mimickers were less likely to be discharged with cardiac medications compared with obstructive disease. At 5-year follow-up, mortality in STEMI presenting with obstructive disease (1228 participants [16%]) was similar to MINOCA (20 participants [18%]; χ21 = 1.1; log-rank P = .29) and MINOCA mimickers (52 participants [18%]; χ21 = 2.3; log-rank P = .13). In adjusted Cox regression analysis compared with obstructive disease, the 5-year mortality hazard risk was 1.93 times higher in MINOCA (95% CI, 1.06-3.53) and similar in MINOCA mimickers (HR, 1.08; 95% CI, 0.79-1.49). Conclusions and Relevance: In this large multicenter cohort study of consecutive clinical patients with STEMI, presenting with MINOCA was associated with a higher risk of mortality than obstructive disease; the risk of mortality was similar in patients with MINOCA mimickers and obstructive disease. Further investigation is necessary to understand the pathophysiologic mechanisms involved in this high-risk STEMI population.

Post-Shock Asystole in Patients Dying Out of Hospital While Wearing a Cardioverter Defibrillator.

BACKGROUND: The wearable cardioverter-defibrillator (WCD) prevents sudden cardiac death due to ventricular tachycardia (VT) or ventricular fibrillation (VF) but does not pace for post-shock asystole (PS-A) or bradycardia (PS-B;<50 beats/ min). OBJECTIVES: The purpose of this study was to assess PS-A and PS-B in patients dying out of hospital (OOH) while wearing a WCD. METHODS: The database of the U.S. Food and Drug Administration Manufacturers and User Facility Device Experience (MAUDE) was queried for manufacturers' reports of OOH deaths while patients were wearing a WCD. Excluded were patients who did not receive a shock or were initially shocked for asystole or during resuscitation. RESULTS: From January 2017 to March 2022, 313 patients received an initial WCD shock for VF (n = 150), VT (n = 90), and non-VF/VT rhythms (n = 73). PS-A occurred in 204 patients (65.2%), and PS-B occurred in 111 (35.5%); 85 (41.7%) PS-A patients also had PS-B. Most PS-A patients (n = 185; 90.7%) had an initial shocked rhythm of VF or VT, but 19 patients (9.3%) were initially inappropriately shocked for atrial fibrillation/supraventricular tachycardia (n = 7) and idioventricular (n = 8) or sinus (n = 4) rhythm. PS-A occurred after the first WCD shock in 118 (63.8%) and after the first, second, or third shocks in 159 patients (85.9%). Seven patients had post-shock heart block. Eight patients had permanent pacemakers; 1 became nonfunctional after 1 shock, and 7 showed noncapture and/or asystole after 1 to 4 shocks. CONCLUSIONS: Post-shock asystole appears to be common in patients who die OOH after being shocked by a WCD for VF or VT. PS-A also occurs after inappropriate WCD shocks for non-VF/VT rhythms. Implanted pacemakers may not prevent PS-A after a WCD shock. WCD backup pacing should be explored.

Association of triglyceride levels with adverse cardiovascular events in patients with ST-segment elevation myocardial infarction.

Although there is an established association between elevated triglyceride (eTG, ≥175 mg/dl) levels and adverse cardiovascular events, some studies have suggested that eTG levels may be linked to neutral or even improved clinical outcomes, particularly among patients with acute myocardial infarction. However, these studies had certain limitations, including small sample sizes, heterogeneous study populations, and inadequate statistical adjustments. To address these limitations, we conducted an analysis of 5347 patients with ST-segment elevation myocardial infarction (STEMI) between March 2003 and December 2020, using a prospective registry-based cohort from two large, regional STEMI centers. We used a triglyceride level of 175 mg/dl as the cutoff point for eTG levels. Of the study participants, 24.5% (n = 1312) had eTG levels. These patients were more likely to be younger, male, and have a higher number of cardiovascular risk factors compared to those with low TG levels. Despite these unfavorable cardiovascular risk profiles, patients with eTG levels had lower unadjusted risks of 1-year major adverse cardiac events (MACE) -a composite of myocardial infarction, stroke, and death- than those with low TG levels (8.8% vs. 11%, p = 0.034). However, after adjusting for certain clinical factors and lipid profile, eTG levels were not associated with a lower 1-year MACE (aHR: 1.10 (0.71-1.70), p = 0.7). In conclusion, a quarter of STEMI patients had eTG levels and these patients had comparable long-term cardiovascular outcomes compared to those with low TG levels after controlling for clinical factors and lipid profile.

Causes and clinical consequences of inappropriate shocks experienced by patients wearing a cardioverter-defibrillator.

BACKGROUND: The LifeVest® wearable cardioverter-defibrillator (WCD) prevents sudden cardiac death in at-risk patients who are not candidates for an implantable defibrillator. The safety and efficacy of the WCD may be impacted by inappropriate shocks (IAS). OBJECTIVE: The purpose of this study was to assess the causes and clinical consequences of WCD IAS in survivors of IAS events. METHODS: The Food and Drug Administration's Manufacturers and User Facility Device Experience database was searched for IAS adverse events (AE) that were reported during 2021 and 2022. RESULTS: A total of 2568 IAS-AE were found (average number of IAS per event: 1.5 ± 1.9; range 1-48). IAS were caused by tachycardias (1255 [48.9%]), motion artifacts (840 [32.7%]), and oversensing (OS) of low-level electrical signals (473 [18.4%]) (P <.001). Tachycardias included atrial fibrillation (AF) (828 [32.2%]), supraventricular tachycardia (SVT) (333 [13.0%]), and nonsustained ventricular tachycardia/fibrillation (NSVT/VF) (87 [3.4%]). Activities responsible for motion-induced IAS included riding a motorcycle, lawnmower, or tractor (n = 128). In 19 patients, IAS induced sustained ventricular tachycardia or ventricular fibrillation that subsequently were terminated by appropriate WCD shocks. Thirty patients fell and suffered physical injuries. Conscious patients (n = 1905) did not use the response buttons to abort shocks (47.9%) or used them improperly (20.2%). IAS resulted in 1190 emergency room visits or hospitalizations, and 17.3% of patients (421/2440) discontinued the WCD after experiencing IAS, especially multiple IAS. CONCLUSIONS: The LifeVest WCD may deliver IAS caused by AF, SVT, NSVT/VF, motion artifacts, and oversensing of electrical signals. These shocks may be arrhythmogenic, result in injuries, precipitate WCD discontinuation, and consume medical resources. Improved WCD sensing, rhythm discrimination, and methods to abort IAS are needed.

Characteristics and Long-term Mortality in Patients with ST-Segment Elevation Myocardial Infarction with Non-Obstructive Coronary Arteries (STE-MINOCA): A High Risk Cohort.

Background: The prognosis of ST-segment elevation myocardial infarction with non-obstructive coronaries (STE-MINOCA) is largely unknown. Methods: The objective of this study is to evaluate the prevalence, characteristics, and 5-year mortality of patients with STE-MINOCA compared to STEMI with coronary artery obstruction (STEMI-Obstruction) using a multicenter cohort of consecutive STEMI patients at 3 regional Midwest STEMI programs from 2003 to 2020. STE-MINOCA was defined based on (1) coronary stenosis < 60% by visual estimation, (2) ischemia with elevated troponin, and (3) no alternative diagnosis. STE-MINOCA was further classified based on American Heart Association (AHA) definition as AHA STE-MINOCA and AHA STE-MINOCA Mimicker. Results: 8,566 STEMI patients, including 420 (4.9%) STE-MINOCA (26.9% AHA STE-MINOCA and 73.1% AHA STE-MINOCA Mimicker) were followed for a median of 7.1 years. Compared to STEMI-Obstruction, STE-MINOCA were younger, more often female, had fewer cardiovascular risk factors, and were less likely to be discharged on cardiac medications. At five years, mortality was higher in STE-MINOCA compared with STEMI-Obstruction (18% vs. 15%, p=0.033). In propensity score-matched analysis, STE-MINOCA had a 1.4-fold (95% CI: 1.04-1.89, p=0.028) higher risk of 5-year all-cause mortality compared with STEMI-Obstruction. Furthermore, 5-year mortality risk was significantly higher in AHA STE-MINOCA Mimicker (19% vs. 15%, p=0.043) but similar in AHA STE-MINOCA (17% vs. 15%, p=0.42) compared with STEMI-Obstruction. Conclusions: In this large multicenter STEMI cohort, nearly 5% of patients presented with STE-MINOCA. At five years, mortality approached 20% among patients with STE-MINOCA. Despite the lower risk profile, STE-MINOCA patients were at 40% higher risk of 5-year all-cause mortality compared with STEMI-Obstruction. Additionally, 5-year all-cause mortality risk was higher in AHA STE-MINOCA Mimicker but similar in AHA STE-MINOCA compared to STEMI-Obstruction.

Frequency and outcomes of STEMI patients presenting between 12 and 24 h after symptom onset: Late-presenting STEMI.

OBJECTIVES: To assess the characteristics and prognosis of ST-elevation myocardial infarction (STEMI) patients, presenting between 12 and 24 h after symptom onset, in contemporary regional STEMI systems of care in the United States. BACKGROUND: Previous observational studies have been inconsistent regarding the benefit of primary percutaneous coronary intervention (PCI) compared with conservative management for late-presenting STEMI patients and the majority of randomized trials are from the fibrinolytic era. METHODS: Using a two-center registry-based cohort from March 2003 to December 2020, we evaluated the frequency, clinical characteristics, and outcomes of STEMI patients, stratified by symptom onset to balloon time: <3, 3-6, 6-12, and 12-24 h (late presenters). RESULTS: Among 5427 STEMI patients with available symptom onset time, 6.2% were late presenters, which increased to 11% during the early phase of the Covid-19 pandemic. As symptom onset to balloon time increased, patients were more likely to be older, female, and have a history of hypertension and diabetes mellitus. Late presenters with an identifiable culprit lesion were less likely to be revascularized with PCI (96%, 96%, 95%, and 92%; p for trend = 0.004) and had a longer median door-to-balloon time (82, 109, 107, and 117 min; p for trend < 0.001). In-hospital and 1-year death risks were comparable between late and earlier presenters. CONCLUSION: Despite the unfavorable risk profile and longer door-to-balloon time, clinical outcomes of late presenters were similar to those presenting within 12 h of symptom onset.

The impact of ST-segment elevation on the prognosis of patients with Takotsubo cardiomyopathy.

INTRODUCTION: Takotsubo cardiomyopathy (TC) has a variety of electrocardiographic expressions such as ST-segment elevation (STE), T-wave inversion, QTc-prolongation, left bundle branch block, presence of anterior Q waves and rarely ST-segment depression. In contrast to acute myocardial infarction, the impact of STE on the initial electrocardiogram (EKG), on TC outcomes, remains largely unknown. OBJECTIVE: To evaluate the significance of STE on the index EKG of patients with takotsubo cardiomyopathy (TC) in terms of prognosis. METHODS: We examined retrospectively the data of 436 patients diagnosed with TC who were admitted to the Minneapolis Heart Institute between August 2001 and November 2019. RESULTS: Of 436 patients, 145 (33%) presented with STE on the index EKG. Typical apical ballooning pattern was encountered more frequently in the STE group (66% vs 51%; p = 0.005), on the contrary to the mid-ventricular ballooning which was more common in the non-STE group (31% vs 45%; p = 0.005) while initial left ventricular ejection fraction was similar between the two groups (31% ± 9 vs 33% ± 11; p = 0.163). The composite endpoint of TC-related complications, defined as left ventricular outflow tract obstruction (LVOTO), left ventricular (LV) thrombus, hemodynamic instability requiring mechanical or intravenous vasopressor support, cardiac arrest or in-hospital death, was higher for the STE group (37% vs 24%; p = 0.006). Left ventricular outflow obstruction (LVOTO) was more frequent in patients with STE (13% vs 3%; p < 0.001) while there was a trend toward higher rates of LV thrombus formation in the same group (5% vs 1%; p = 0.057). On multivariable analysis, STE remained an independent predictor of TC-related complications. In-hospital mortality (2.8% vs 3.4%; p = 1.000) and five-year mortality were similar between the two groups (23% vs 20%; p = 0.612). CONCLUSION: Patients with TC presenting with STE on the initial EKG, were more likely to develop disease related complications, thus, careful in-hospital monitoring including imaging evaluation for LVOTO and LV thrombus may be warranted for these patients. Nevertheless, both groups had similar in-hospital and five-year mortality.

Revascularization and long-term outcomes in high-acuity spontaneous coronary artery dissection.

BACKGROUND: Spontaneous coronary artery dissection (SCAD) is often treated conservatively due to revascularization risks. Yet, an important number of SCAD patients have high acuity characteristics necessitating revascularization, with uncertain long-term outcomes. OBJECTIVES: Document revascularization utilization and long-term outcomes in high acuity SCAD. METHODS: Prospective/retrospective analysis of consecutive patients with acute myocardial infarction (AMI) due to first SCAD event presenting directly to the Minneapolis Heart Institute 2002-2021, median follow-up 3.8 years. RESULTS: Among 139 patients (age 49 ± 12 years, 96% female), revascularization was performed in 60 (43%), utilizing percutaneous coronary intervention (PCI) (n = 56, successful in 80%) or coronary artery bypass graft (n = 4). In the entire cohort, 90 (65%) unique patients had one or more high acuity characteristic: ST-elevation (38%), proximal dissection (38%), cardiogenic shock (6.5%), cardiac arrest (9.4%), left main dissection (6.5%), peripartum dissection (7.2%). High acuity patients accounted for 51 of 60 (85%) revascularizations. Revascularization rates were: ST-elevation (60%), proximal dissection (62%), cardiogenic shock (89%), cardiac arrest (62%), left main dissection (100%), peripartum dissection (70%). Survival was 97% (revascularized) vs 100% (nonrevascularized); p = 0.2. Adverse outcomes (revascularized vs. nonrevascularized) included recurrent AMI:16.7% versus 8.9%; p = 0.2, SCAD recurrence: 13.3% versus 6.3%; p = 0.1, stroke: 5% versus 2.5%; p = 0.44, implantable cardioverter-defibrillator: 6.7% versus 6.3%; p > 0.9. Reintervention was necessary in 21% of PCI-treated patients. CONCLUSIONS: High-acuity characteristics were present in nearly two-thirds of this SCAD cohort; the vast majority of revascularizations were performed in high-acuity patients. Despite high acuity, long-term survival was favorable in revascularized patients.

STEMI: Considerations for Left Main Culprit Lesions.

PURPOSE OF REVIEW: There is a paucity of data regarding the prevalence, clinical characteristics, and outcomes of patients presenting with ST elevation myocardial infarction (STEMI) due to left main (LM) culprit vessel. RECENT FINDINGS: LM culprit STEMI (LMCSTEMI) is an uncommon, but frequently catastrophic event. Prior meta-analyses and registries have described a varying prevalence of LMCSTEMI, associated cardiogenic shock, and in-hospital mortality among those surviving to hospital presentation. These observed clinical discrepancies may be partially attributable to diverse clinical and angiographical subsets among this STEMI population. STEMI due to LM culprit artery disease represents a clinically high-risk subset of patients with substantial in-hospital mortality. In this paper, we summarize the available clinical data pertaining to STEMI with LM culprit, discuss unique ECG characteristics, and discuss contemporary revascularization therapy. We also report the preliminary findings from a contemporary, STEMI database describing clinical characteristics and angiographically defined subsets of LM culprit STEMI.

Variability in reporting of key outcome predictors in acute myocardial infarction cardiogenic shock trials.

BACKGROUND: Among acute myocardial infarction patients with cardiogenic shock (AMICS), a number of key variables predict mortality, including cardiac arrest (CA) and shock classification as proposed by Society for Cardiovascular Angiography and Intervention (SCAI). Given this prognostic importance, we examined the frequency of reporting of high risk variables in published randomized controlled trials (RCTs) of AMICS patients. METHODS: We identified 15 RCTs enrolling 2,500 AMICS patients and then reviewed rates of CA, baseline neurologic status, right heart catheterization data, lactate levels, inotrope and vasopressor requirement, hypothermia, mechanical ventilation, left ventricular ejection fraction (LVEF), mechanical circulatory support, and specific cause of death based on the primary manuscript and Data in S1. RESULTS: A total of 2,500 AMICS patients have been enrolled in 15 clinical trials over 21 years with only four trials enrolling >80 patients. The reporting frequency and range for key prognostic factors was: neurologic status (0% reported), hypothermia (28% reported, prevalence 33-75%), specific cause of death (33% reported), cardiac index and wedge pressure (47% reported, range 1.6-2.3 L min-1  m-2 and 15-24 mmHg), lactate (60% reported, range 4-7.7 mmol/L), LVEF (73% reported, range 25-45%), CA (80% reported, prevalence 0-92%), MCS (80% reported, prevalence 13-100%), and mechanical ventilation (93% reported, prevalence 35-100%). This variability was reflected in the 30-day mortality which ranged from 20-73%. CONCLUSIONS: In a comprehensive review of seminal RCTs in AMICS, important predictors of outcome were frequently not reported. Future efforts to standardize CS trial data collection and reporting may allow for better assessment of novel therapies for AMICS.

Frequency, Etiology, and Impact of Unplanned Repeat Coronary Angiography After ST-Elevation Myocardial Infarction.

Unplanned repeat coronary angiography (CAG) after balloon angioplasty for ST-elevation myocardial infarction (STEMI) was common before the advent of coronary stenting. Limited data are available regarding the role of unplanned repeat CAG in contemporary percutaneous coronary intervention (PCI) for STEMI. Therefore, we analyzed a large, 2-center prospective STEMI registry (January 2011 to June 2020) stratified by the presence or absence of unplanned repeat CAG during index hospitalization. Patients with planned CAG for staged PCI or experimental drug administration were excluded. Among 3,637 patients with STEMI, 130 underwent unplanned repeat CAG (3.6%) during index hospitalization. These patients were more likely to have cardiogenic shock (16% vs 9.8%, p = 0.021), left anterior descending culprit (44% vs 31%, p <0.001), lower left ventricular ejection fraction (45% vs 52%, p <0.001), and higher peak troponin levels (22 vs 8 ng/ml, p <0.001) than those without repeat CAG. At repeat CAG, 80 patients had a patent stent (62%) including 65 requiring no further intervention (50%) and 15 who underwent intervention on a nonculprit lesion (12%). Only 32 patients had stent thrombosis (25%). Repeat CAG was associated with a higher incidence of recurrent MI (19% vs 0%, p <0.001) and major bleeding (12% vs 4.5%, p <0.001), yet similar in-hospital mortality (7% vs 6.4%, p = 0.93) than those without repeat CAG. In conclusion, in the era of contemporary PCI for STEMI, unplanned repeat CAG during index hospitalization was infrequent and more commonly observed in patients with left anterior descending culprit in the presence of significant left ventricular dysfunction or shock and was associated with higher in-hospital recurrent myocardial infarction and major bleeding complications.

The impact of regional STEMI systems on protocol use and quality improvement initiatives in community hospitals without cardiac catheterization laboratories.

Study objective: Since the 1990s, national guidelines have recommended hospitals develop STEMI treatment protocols and monitor quality. A 2003 survey of Minnesota hospitals without cardiac catheterization laboratories (CCL) found <2/3 had STEMI protocols, <50% had a quality assessment (QA) process, and protocols in existence were incomplete. We evaluated temporal changes in STEMI processes in relationship to changes in mortality. Design setting and participants: Follow-up surveys were mailed to emergency departments at 108 Minnesota hospitals without CCL. Results: Among 87% of responding hospitals, 89% had formal protocols or guidelines for STEMI management compared to 63% in 2003 (p < 0.001). In 2010, 67% of hospitals had triage/transfer criteria and 15% of hospitals used protocols for transfer decisions, compared to only 8% (p < 0.001) and 1% (p = 0.098), respectively, in 2003. The percentage of hospitals transferring patients with STEMI from the emergency department increased from 23% in 2003 to 56% in 2010 (p < 0.001). During this time, age-adjusted acute MI mortality rate in Minnesota decreased 33% and was more pronounced in areas with regional STEMI systems. Conclusions: Since 2003, utilization of STEMI guidelines, protocols, and standing orders in Minnesota hospitals without CCL has markedly improved with <10% of hospitals lacking specific STEMI management protocols. The majority of hospitals routinely transfer patients with STEMI for primary PCI and have comprehensive QA processes. This improvement was stimulated by regional STEMI systems, further supporting the current class I recommendation for STEMI systems of care in current guidelines. The decline in Minnesota STEMI mortality paralleled the growth of regional STEMI systems.

Acute Myocardial Infarction-Like Events in Related Patients With a Desmoplakin-Associated Arrhythmogenic Cardiomyopathy.

Patients with familial arrhythmogenic cardiomyopathy typically present with ventricular arrhythmias or progressive heart failure. This paper characterizes a rare presentation of an underlying genetic cardiomyopathy with clinical manifestations mimicking an acute myocardial infarction in 2 siblings, each with the same mutation in the desmoplakin (DSP) gene. (Level of Difficulty: Advanced.).

Recognition of acute myocardial infarction caused by spontaneous coronary artery dissection of first septal perforator.

AIMS: Spontaneous coronary artery dissection (SCAD) diagnosis is challenging as angiographic findings are often subtle and differ from coronary atherosclerosis. Herein, we describe characteristics of patients with acute myocardial infarction (MI) caused by first septal perforator (S1) SCAD. METHODS AND RESULTS: Patients were gathered from SCAD registries at Minneapolis Heart Institute and Vancouver General Hospital. First septal perforator SCAD prevalence was 11 of 1490 (0.7%). Among 11 patients, age range was 38-64 years, 9 (82%) were female. Each presented with acute chest pain, troponin elevation, and non-ST-elevation MI diagnosis. Initial electrocardiogram demonstrated ischaemia in 5 (45%); septal wall motion abnormality was present in 4 (36%). Angiographic type 2 SCAD was present in 7 (64%) patients with S1 TIMI 3 flow in 7 (64%) and TIMI 0 flow in 2 (18%). Initial angiographic interpretation failed to recognize S1-SCAD in 6 (55%) patients (no culprit, n = 5, septal embolism, n = 1). First septal perforator SCAD diagnosis was established by review of initial coronary angiogram consequent to cardiovascular magnetic resonance (CMR) demonstrating focal septal late gadolinium enhancement with corresponding oedema (n = 3), occurrence of subsequent SCAD event (n = 2), or second angiogram showing healed S1-SCAD (n = 1). Patients were treated conservatively, each with ejection fraction >50%. CONCLUSION: First septal perforator SCAD events may be overlooked at initial angiography and mis-diagnosed as 'no culprit' MI. First septal perforator SCAD prevalence is likely greater than reported herein and dependent on local expertise and availability of CMR imaging. Spontaneous coronary artery dissection events may occur in intra-myocardial coronary arteries, approaching the resolution limits of invasive coronary angiography.