Elevated Troponins and Diagnosis of Non-ST-Elevation Myocardial Infarction in the Emergency Department.

Background In the emergency department (ED), the diagnosis of non-ST-elevation myocardial infarction (NSTEMI) is primarily based on the presence or absence of elevated cardiac troponin levels, ECG changes, and clinical presentation. However, limited data exist regarding the incidence, clinical characteristics, and predictive value of different cardiac diagnostic tests and outcomes in patients with non-acute coronary syndrome (ACS)-related troponin elevation. Our study aimed to determine the percentage of patients with elevated troponin levels who had true ACS and identify various risk factors associated with true ACS in these patients. Methodology This was a single-center retrospective study. We performed a chart review of patients who presented to the ED from January 1, 2016, to December 31, 2017, and were admitted to the hospital with an elevated cardiac troponin I level in the first 12 hours after ED presentation with a diagnosis of NSTEMI. True ACS was defined as (a) patients with typical symptoms of ischemia and ECG ischemic changes and (b) patients with atypical symptoms of myocardial ischemia or without symptoms of ischemia and new segmental wall motion abnormalities on echocardiogram or evidence of culprit lesion on angiography. A logistic regression model was used to determine the association between risk factors and true ACS. Results A total of 204 patients were included in this study. The mean age of the study group was 67.4 ± 14.5 years; 53.4% (n = 109) were male, and 57.4% (n = 117) were Caucasian. In our study, 51% of patients were found to have true ACS, and the remaining 49% had a non-ACS-related elevation in troponins. Most patients without ACS had alternate explanations for elevated troponin levels. The presence of chest pain (odds ratio (OR) = 3.7, 95% confidence interval (CI) = 1.8-7.7, p = 0.001), tobacco smoking (OR = 4, 95% CI = 1.06-3.8, p = 0.032), and wall motion abnormalities on echocardiogram (OR = 3.8, 95% CI = 1.8-6.5, p = 001) were associated with increased risk of true ACS in patients with elevated troponins. Conclusions Cardiac troponin levels can be elevated in hospitalized patients with various medical conditions, in the absence of ACS. The diagnosis of ACS should not be solely based on elevated troponin levels, as it can lead to expensive workup and utilization of hospital resources.

Trends and outcomes of percutaneous coronary intervention during the COVID-19 pandemic in Michigan.

BACKGROUND: The COVID-19 pandemic has severely impacted healthcare delivery and patient outcomes globally. AIMS: We aimed to evaluate the influence of the COVID-19 pandemic on the temporal trends and outcomes of patients undergoing percutaneous coronary intervention (PCI) in Michigan. METHODS: We compared all patients undergoing PCI in the BMC2 Registry between March and December 2020 ("pandemic cohort") with those undergoing PCI between March and December 2019 ("pre-pandemic cohort"). A risk-adjusted analysis of in-hospital outcomes was performed between the pre-pandemic and pandemic cohort. A subgroup analysis was performed comparing COVID-19 positive vs. negative patients during the pandemic. RESULTS: There was a 15.2% reduction in overall PCI volume from the pre-pandemic (n = 25,737) to the pandemic cohort (n = 21,822), which was more pronounced for stable angina and non-ST-elevation acute coronary syndromes (ACS) presentations, and between February and May 2020. Patients in the two cohorts had similar clinical and procedural characteristics. Monthly mortality rates for primary PCI were generally higher in the pandemic period. There were no significant system delays in care between the cohorts. Risk-adjusted mortality was higher in the pandemic cohort (aOR 1.26, 95% CI 1.07-1.47, p = 0.005), a finding that was only partially explained by worse outcomes in COVID-19 patients and was more pronounced in subjects with ACS. During the pandemic, COVID-19 positive patients suffered higher risk-adjusted mortality (aOR 5.69, 95% CI 2.54-12.74, p<0.001) compared with COVID negative patients. CONCLUSIONS: During the COVID-19 pandemic, we observed a reduction in PCI volumes and higher risk-adjusted mortality. COVID-19 positive patients experienced significantly worse outcomes.

Prevalence of coronary risk factors in contemporary practice among patients undergoing their first percutaneous coronary intervention: Implications for primary prevention.

BACKGROUND: Cigarette smoking, hypertension, dyslipidemia, diabetes, and obesity are conventional risk factors (RFs) for coronary artery disease (CAD). Population trends for these RFs have varied in recent decades. Consequently, the risk factor profile for patients presenting with a new diagnosis of CAD in contemporary practice remains unknown. OBJECTIVES: To examine the prevalence of RFs and their temporal trends among patients without a history of myocardial infarction or revascularization who underwent their first percutaneous coronary intervention (PCI). METHODS: We examined the prevalence and temporal trends of RFs among patients without a history of prior myocardial infarction, PCI, or coronary artery bypass graft surgery who underwent PCI at 47 non-federal hospitals in Michigan between 1/1/2010 and 3/31/2018. RESULTS: Of 69,571 men and 38,930 women in the study cohort, 95.5% of patients had 1 or more RFs and nearly half (55.2% of women and 48.7% of men) had ≥3 RFs. The gap in the mean age at the time of presentation between men and women narrowed as the number of RFs increased with a gap of 6 years among those with 2 RFs to <1 year among those with 5 RFs. Compared with patients without a current/recent history of smoking, those with a current/recent history of smoking presented a decade earlier (age 56.8 versus 66.9 years; p <0.0001). Compared with patients without obesity, patients with obesity presented 4.0 years earlier (age 61.4 years versus 65.4 years; p <0.0001). CONCLUSIONS: Modifiable RFs are widely prevalent among patients undergoing their first PCI. Smoking and obesity are associated with an earlier age of presentation. Population-level interventions aimed at preventing obesity and smoking could significantly delay the onset of CAD and the need for PCI.

Association of Operator and Hospital Experience With Procedural Success Rates and Outcomes in Patients Undergoing Percutaneous Coronary Interventions for Chronic Total Occlusions: Insights From the Blue Cross Blue Shield of Michigan Cardiovascular Consortium.

BACKGROUND: An inverse relationship has been described between procedural success and outcomes of all major cardiovascular procedures. However, this relationship has not been studied for percutaneous coronary intervention (PCI) of chronic total occlusion (CTO). METHODS: We analyzed the data on patients enrolled in Blue Cross Blue Shield of Michigan Cardiovascular Consortium registry in Michigan (January 1, 2010 to March 31, 2018) to evaluate the association of operator and hospital experience with procedural success and outcomes of patients undergoing CTO-PCI. CTO-PCI was defined as intervention of a 100% occluded coronary artery presumed to be ≥3 months old. RESULTS: Among 210 172 patients enrolled in the registry, 7389 (3.5%) CTO-PCIs were attempted with a success rate of 53%. CTO-PCI success increased with operator experience (45% and 65% in the lowest and highest experience tertiles) and was the highest for highly experienced operators at higher experience centers and the lowest for inexperienced operators at low experience hospitals. Multivariable logistic regression models (with spline transformed prior operator and institutional experience) demonstrated a positive relationship between prior operator and site experience and procedural success rates (likelihood ratio test=141.12, df=15, P<0.001) but no relationship between operator and site experience and major adverse cardiac event (likelihood ratio test=19.12, df=15, P=0.208). CONCLUSIONS: Operator and hospital CTO-PCI experiences were directly related to procedural success but were not related to major adverse cardiac event among patients undergoing CTO-PCIs. Inexperienced operators at high experience centers had significantly higher success but not major adverse cardiac event rates compared with inexperienced operators at low experience centers. These data suggested that CTO-PCI safety and success could potentially be improved by selective referral of these procedures to experienced operators working at highly experienced centers.

Percutaneous Coronary Intervention for Chronic Total Occlusion-The Michigan Experience: Insights From the BMC2 Registry.

OBJECTIVES: The aim of this study was to describe the performance and outcomes of chronic total occlusion (CTO) percutaneous coronary intervention (PCI) in Michigan. BACKGROUND: CTO PCI has been associated with reduction in angina, but previous registry analyses showed a higher rate of major adverse cardiac events with this procedure. METHODS: To study uptake and outcomes of CTO PCI in Michigan, patients enrolled in the BMC2 (Blue Cross Blue Shield of Michigan Cardiovascular Consortium) registry (2010 to 2017) were evaluated. CTO PCI was defined as intervention in a 100% occluded coronary artery ≥3 months old. RESULTS: Among 210,172 patients enrolled in the registry, 7,389 CTO PCIs (3.5%) were attempted, with 4,614 (58.3%) achieving post-procedural TIMI (Thrombolysis In Myocardial Infarction) flow grade 3. The proportion of PCIs performed on CTOs increased over the study period (from 2.67% in 2010 to 4.48% in 2017). Thirty of 47 hospitals performed >50 CTO interventions in 2017. Pre-procedural angina class ≤2 was present in one-quarter, and functional assessment for ischemia was performed in 46.6% of patients. Major complications occurred in 245 patients (3.3%) and included death (1.4%), post-procedural stroke (0.4%), cardiac tamponade (0.5%), and urgent coronary artery bypass graft surgery (1.3%). Procedural success improved modestly from 44.5% in 2010 to 54.9% in 2017 (p for trend < 0.001). Rates of in-hospital mortality (p for trend = 0.247) and major adverse cardiac event (p for trend = 0.859) for CTO PCI remained unchanged over the study period. CONCLUSIONS: The rate of CTO PCI in Michigan increased over the study period. Although the success rate of CTO PCI has increased modestly in contemporary practice, it remained far below the >80% reported by select high-volume CTO operators. The rate of periprocedural major adverse cardiac events or death remained unchanged over time. These data suggest room for improvement in the selection and functional assessment of CTO lesions before subjecting patients to the increased procedural risk associated with CTO PCI.

Early Versus Delayed Use of Ultrasound-Assisted Catheter-Directed Thrombolysis in Patients With Acute Submassive Pulmonary Embolism.

OBJECTIVES: The effect of early vs delayed use of ultrasound-assisted catheter-directed thrombolysis (USAT) on invasive hemodynamics and in-hospital outcomes in patients with acute submassive pulmonary embolism (PE) is not well known. METHODS: We evaluated 41 patients with submassive PE to study the association of early USAT (≤24 hours; n = 21) vs delayed USAT (>24 hours; n = 20) with change in invasive hemodynamic measures from pre USAT to post USAT. RESULTS: Significantly greater improvement was observed in the early USAT group compared to the delayed group for median cardiac index (0.6 L/min/m² [IQR, 0.4-1.1 L/min/ m²] vs 0.4 L/min/m² [IQR, 0.1-0.6 L/min/m²]; P=.03), median pulmonary vascular resistance (3.4 Wood units [IQR, 2.5-4.1 Wood units] vs 0.5 Wood units [IQR, 0.2-1.3 Wood units]; P<.001), and mean right ventricular stroke work index (3.5 ± 2.0 g-m/m²/beat vs 2.3 ± 1.6 g-m/m2/beat; P=.04). Although not statistically significant, a trend in favor of early treatment was found for improvement in mean right ventricle to left ventricle diameter ratio (0.38 ± 0.17 vs 0.33 ± 0.21; P=.40), mean pulmonary artery pressure (8.4 ± 7.1 mm Hg vs 5.3 ± 5.2 mm Hg; P=.13), and median pulmonary artery pulsatility index (1.14 [IQR, 2.01-0.45] vs 0.65 [IQR, 0.22-1.78]; P=.49). The mean postprocedural length of stay was significantly lower in the early-USAT group (6.0 ± 2.7 days vs 10.1 ± 7.0 days; P=.02). Three patients experienced moderate bleeding (2 patients in the early-USAT group and 1 patient in the delayed-USAT group) and no major bleeds or in-hospital mortality occurred. CONCLUSION: Early USAT was associated with greater improvement in pulmonary hemodynamics and shorter postprocedural length of stay compared with delayed USAT in patients with acute submassive PE.

An Uncommon Variant of an Uncommon Disease: A Caucasian Adolescent with Apical Hypertrophic Cardiomyopathy Diagnosed with Myocardial Perfusion Imaging.

Apical hypertrophic cardiomyopathy (ApHCM) is a subtype of HCM. This variant is more common in the Asian population when compared to North American patients. Patients may present with arrhythmias, heart failure, myocardial infarction, chest discomfort, fatigue, and presyncope or syncope. Initial evaluation requires electrocardiogram and two-dimensional echocardiogram. T-wave inversion in the precordial leads as well as hypertrophy of the left ventricle is hallmarks of the disease. Cardiac magnetic resonance (CMR) imaging is the most specific and sensitive imaging modality. In patients with contraindications for CMR, myocardial perfusion imaging (MPI) has been described to have diagnostic characteristics for ApHCM. MPI images demonstrating a "solar polar" map pattern and increased apical tracer uptake in single-photon emission computed tomography horizontally and vertical long-axis slices are consistent with the diagnosis of ApHCM. Herein, we present a case of a Caucasian adolescent female who underwent a cardiac screening to rule out hypertrophic obstructive cardiomyopathy. Initially, the patient was unable to undergo CMR, and an MPI was utilized to assist with the diagnosis of ApHCM.

Etiology and pathophysiology of new-onset heart failure: evaluation by myocardial perfusion imaging.

OBJECTIVE: The IMAGING in Heart Failure study was a prospective, multi-national trial designed to explore the role of single-photon emission computed tomographic (SPECT) myocardial perfusion imaging (MPI) as an initial investigative strategy in patients hospitalized with new-onset heart failure. METHODS: We recruited 201 patients (age 65.3 +/- 14.5 years, 43% women) hospitalized with their first episode of heart failure. Rest/stress gated SPECT Tc-99m sestamibi MPI was performed during or within 2 weeks of the index hospitalization, in addition to standard care. RESULTS: SPECT MPI revealed a broad range of ejection fractions with preserved systolic function in 36% of patients. Forty-one percent of patients had normal perfusion. In the remaining patients, perfusion abnormalities were predominantly due to prior myocardial infarction, with extensive ischemia seen only in 6%. Among patients who underwent coronary angiography, SPECT performance characteristics revealed excellent negative predictive value (96%) for extensive coronary artery disease (CAD). In multivariable analyses, the extent of perfusion abnormality and advancing age predicted the presence of extensive CAD. CONCLUSIONS: These preliminary data derived from a non-randomized observational cohort suggest potential diagnostic utility of MPI for ischemic LV dysfunction in new-onset HF, and sets the stage for a prospective randomized study to confirm these findings.

Effect of a peroxisome proliferator-activated receptor-gamma agonist on myocardial blood flow in type 2 diabetes.

OBJECTIVE: The relationship between coronary endothelial function and insulin resistance remains speculative. We sought to determine whether pioglitazone, an insulin-sensitizing peroxisome proliferator-activated receptor (PPAR)-gamma agonist, improves cardiac endothelial function in individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS: Sixteen subjects with insulin-treated type 2 diabetes and without overt cardiovascular disease were randomly assigned to receive either 45 mg of pioglitazone or matching placebo for 3 months. Rest and adenosine-stimulated myocardial blood flow (MBF) were quantified with [(13)N]ammonia and positron emission tomography at baseline and study conclusion. RESULTS: After 3 months, HbA(1c) levels dropped by 0.68% in the pioglitazone group and increased by 0.17% in the placebo group (P = 0.009 for difference between groups). Triglyceride (-93 vs. -39 mg/dl, P = 0.026) and HDL concentrations (+4.8 vs. -6.0 mg/dl, P = 0.014) improved significantly in the pioglitazone group compared with placebo. Despite these favorable changes, there was no demonstrable change in baseline MBF (-0.05 +/- 0.24 vs. -0.09 +/- 0.24 ml . min(-1) . g(-1), P = 0.45), adenosine-stimulated MBF (0.10 +/- 0.75 vs. 0.14 +/- 0.31 ml . min(-1) . g(-1), P = 0.25), or coronary flow reserve (0.45 +/- 1.22 vs. 0.35 +/- 0.72 ml . min(-1) . g(-1), P = 0.64) after 12 weeks of exposure to pioglitazone or placebo, respectively. Regression analysis revealed that lower glucose concentration at the time of the study was associated with higher coronary flow reserve (P = 0.012). CONCLUSIONS: Pioglitazone treatment for 12 weeks in subjects with insulin-requiring type 2 diabetes had no demonstrable effect on coronary flow reserve despite metabolic improvements. Higher ambient glucose levels contribute to impaired vascular reactivity in individuals with diabetes.

Pilot study of a Web-based compliance monitoring device for patients with congestive heart failure.

BACKGROUND: Web-based home care monitoring systems can assess medication compliance, health status, quality of life, and physiologic parameters. They may help overcome some of the limitations associated with current congestive heart failure management models. OBJECTIVES: This pilot study compared the effects of a self-care and medication compliance device, linked to a Web-based monitoring system, to the effects of usual care alone on compliance with recommended self-care behaviors; medication taking; quality of life; distance walked during a 6-minute walk test; and New York Heart Association Functional Class. We also assessed patient experiences living with the compliance device. METHODS: We enrolled 18 patients with Functional Class II-III congestive heart failure in an urban VA Medical Center. The patients were randomized into 2 groups. Group A received usual care plus the compliance device. Group B (controls) received usual care only. Data were collected using the compliance device, the Heart Failure Self-Care Behavior Scale, pill counts, 6-minute walk test, and the Minnesota Living with Heart Failure Questionnaire at baseline and at 3 months follow-up. RESULTS: At baseline and at 3 months, there were no differences between the compliance device group and the usual care group in self-care behaviors, pill counts, 6-minute walk-test distance, or Functional Class. However, quality of life improved significantly from baseline to 3-month follow-up (ANOVA, P =.006). This difference was due to an improvement in quality of life for the monitor group (P =.002) but not the usual care only group (P =.113). Patients in the compliance device group had a 94% medication compliance rate, 81% compliance with daily blood pressure monitoring, and 85% compliance with daily weight monitoring as compared to 51% for blood pressure monitoring and 79% for weight monitoring in the usual care group (P = NS). CONCLUSION: These are promising pilot results that, if replicated in a larger sample, may significantly improve care and outcomes for patients with heart failure.

Correlation of myocardial p-(123)I-iodophenylpentadecanoic acid retention with (18)F-FDG accumulation during experimental low-flow ischemia.

UNLABELLED: Myocardial ischemia is associated with reduced free fatty acid (FFA) beta-oxidation and increased glucose utilization. This study evaluated the potential of dynamic SPECT imaging of a FFA analog, p-(123)I-iodophenylpentadecanoic acid (IPPA), for detection of ischemia and compares retention of IPPA with (18)F-FDG accumulation. METHODS: In a canine model of regional low-flow ischemia (n = 9), serial IPPA SPECT images (2 min per image) were acquired over 52--90 min. In a subset of dogs (n = 6), (18)F-FDG was injected after completing SPECT imaging and allowed to accumulate for 40 min before killing the animals. Flow was assessed with radiolabeled microspheres. Myocardial metabolism was evaluated independently by selective coronary arterial and venous sampling. RESULTS: Serial IPPA SPECT images showed an initial defect in the ischemic region (0.70% plus minus 0.03% ischemic-to-nonischemic ratio), which normalized within 48 min because of the slower IPPA clearance from the ischemic region (t(1/2) = 54.2 plus minus 3.3 min) relative to the nonischemic region (t(1/2) = 36.7 plus minus 5.6 min) (P < 0.05). Delayed myocardial IPPA and (18)F-FDG activities were correlated (r = 0.70; n = 576 segments), and both were maximally increased in segments with a moderate flow reduction (IPPA, 151% of nonischemic; (18)F-FDG, 450% of nonischemic; P < 0.05). CONCLUSION: Serial SPECT imaging showed delayed myocardial clearance of IPPA in ischemic regions with moderate flow reduction, which lead to increased late myocardial retention of IPPA. Retention of IPPA correlated with (18)F-FDG accumulation, supporting the potential of IPPA as a noninvasive marker of ischemic myocardium.