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Background: Rapid activation of a cardiac catheterization laboratory (CCL) has reduced door-to-balloon times in ST-segment elevation myocardial infarction (STEMI), leading to lower mortality. This process is accelerated with prehospital electrocardiography and notification. False activations of the CCL occur at an unknown rate and have been poorly described., Methods and Results: We analyzed 345 consecutive CCL activations for suspected STEMI over 18 months (March 2009-August 2010). We retrospectively reviewed the ECGs that prompted activation, as well as the clinical course and final diagnoses. Among all CCL activations, STEMI was not confirmed in 28%. On review, 301 (87.2%) had appropriate ECG criteria for activation. However, even among the ECG-appropriate patients, only 247 (82%) had a final diagnosis of STEMI. The inclusion of clinical characteristics did not improve the ability to identify patients with STEMI. Activations were modestly more accurate when made by emergency department physicians than by emergency medical service personnel, but door-to-balloon time was noticeably shorter when emergency medical service personnel requested prehospital activation., Conclusions: If all CCL activations are considered, the occurrence of false activations is surprisingly high. Although still the gold standard for diagnosis, these data reveal the inherent limitations of clinical evaluation and the ECG in identifying patients with STEMI. Within our retrospective review, we used a 2-tiered classification for STEMI activations based on ECG appropriateness and final clinical diagnosis to give a complete picture of false activations and assist in quality improvement.

Context: Despite the widespread use of percutaneous coronary intervention (PCI), the appropriateness of these procedures in contemporary practice is unknown., Objective: To assess the appropriateness of PCI in the United States., Design, Setting, and Patients: Multicenter, prospective study of patients within the National Cardiovascular Data Registry undergoing PCI between July 1, 2009, and September 30, 2010, at 1091 US hospitals. The appropriateness of PCI was adjudicated using the appropriate use criteria for coronary revascularization. Results were stratified by whether the procedure was performed for an acute (ST-segment elevation myocardial infarction, non-ST-segment elevation myocardial infarction, or unstable angina with high-risk features) or nonacute indication., Main Outcome Measures: Proportion of acute and nonacute PCIs classified as appropriate, uncertain, or inappropriate; extent of hospital-level variation in inappropriate procedures., Results: Of 500,154 PCIs, 355,417 (71.1%) were for acute indications (ST-segment elevation myocardial infarction, 103,245 [20.6%]; non-ST-segment elevation myocardial infarction, 105,708 [21.1%]; high-risk unstable angina, 146,464 [29.3%]), and 144,737 (28.9%) for nonacute indications. For acute indications, 350,469 PCIs (98.6%) were classified as appropriate, 1055 (0.3%) as uncertain, and 3893 (1.1%) as inappropriate. For nonacute indications, 72,911 PCIs (50.4%) were classified as appropriate, 54,988 (38.0%) as uncertain, and 16,838 (11.6%) as inappropriate. The majority of inappropriate PCIs for nonacute indications were performed in patients with no angina (53.8%), low-risk ischemia on noninvasive stress testing (71.6%), or suboptimal (≤1 medication) antianginal therapy (95.8%). Furthermore, although variation in the proportion of inappropriate PCI across hospitals was minimal for acute procedures, there was substantial hospital variation for nonacute procedures (median hospital rate for inappropriate PCI, 10.8%; interquartile range, 6.0%-16.7%)., Conclusions: In this large contemporary US cohort, nearly all acute PCIs were classified as appropriate. For nonacute indications, however, 12% were classified as inappropriate, with substantial variation across hospitals.

Although accepted in several countries abroad, the performance of percutaneous coronary intervention (PCI) without onsite surgical backup is controversial in the United States. Current guidelines from the United States do not endorse elective PCI in facilities without onsite surgical backup but acknowledge that primary PCI for ST-segment elevation myocardial infarction is acceptable under carefully regulated and monitored circumstances. This differs from guidelines developed by organizations in other countries. In the United States, data indicate that primary alone or primary and elective PCI without onsite surgery is currently being performed in all but seven states, and the number of patients treated in this setting is increasing. More than 40 articles reporting the outcomes and safety of PCI without onsite surgical backup have been published, but these are from a limited number of centers and are retrospective reviews or prospective registries, which have inherent limitations. Additional studies are currently under way to evaluate PCI's safety and effectiveness in this setting.

The practice of performing percutaneous coronary intervention (PCI) in centers without on-site cardiac surgical backup is controversial. Using data from facilities that participated in the American College of Cardiology/National Cardiovascular Data Registry, the incidence of PCI without on-site surgical backup was evaluated. From January 1, 2001 through December 31, 2004, 39 of 449 (8.7%) centers were identified as sites that performed PCI without on-site surgical backup. By the end of 2005, 75 of 463 (16%) participating facilities were performing PCI without on-site backup. By using standardized data element definitions, it was possible to differentiate between patients who underwent elective PCI and those who had urgent nonelective PCI for acute ST-segment elevation myocardial infarction or non-ST-segment elevation myocardial infarction. This analysis showed that the number of elective and nonelective PCI procedures with or without on-site surgical backup per quarter had increased significantly (p <0.0001) from 2001 to 2004. The number of PCI procedures performed without on-site surgical backup continued to increase in 2005. In conclusion, the significant increase in elective PCIs performed at facilities without on-site surgical backup occurred despite national guidelines that state elective PCI should not be done in centers without on-site cardiac surgery.

Previous studies have demonstrated variation in vascular events with respect to season and time of day. Changes in barometric pressure display daily and seasonal variations and could modulate the occurrence of vascular events. The objective of this study was to determine whether a relation exists between changes in barometric pressure and occurrence of stroke or acute myocardial infarction (AMI). A retrospective analysis of hospital admissions for AMI and stroke from 1993 to 1996 in central Texas was related to changes in atmospheric pressure that were obtained from the National Climatic Data Center. Patients who had AMI (n = 1,327) or stroke (n = 839) were identified from a computerized hospital database. Mean atmospheric pressure, greatest change in pressure, and rate of change in pressure per 24-hour period were computed. One-, 2-, and 3-day and seasonal groupings of cardiovascular events were related to corresponding changes in barometric pressure. The fall and winter seasons had the highest variability in atmospheric pressure readings. There was a significant correlation (p = 0.0083) between a decrease in atmospheric pressure and the occurrence of AMI the day after a pressure decrease, especially during the fall and winter seasons. No relation between stroke and atmospheric pressure was demonstrated. In conclusion, we conclude that rapid decreases in barometric pressure are associated with the occurrence of AMI but not of stroke.

Because coronary angioplasty is being increasingly used as a treatment for coronary artery disease, the proper evaluation and management of patients after the procedure are important issues. Although coronary angioplasty is a complex technical procedure, the methods routinely used to evaluate its results have many shortcomings. Although the initial results of the procedure are assessed most commonly by the visual interpretation of video images and coronary angiograms, quantitative angiography, trans-stenotic pressure gradients, and coronary flow reserve measurements have also been used. In the period after coronary angioplasty, success can be evaluated by patients' clinical improvement in symptoms and their stress responses to various functional tests. The management of the patient during the first 24 hours after angioplasty should focus on the prevention, detection, and, if necessary, treatment of acute vessel closure. During the subsequent 6 months, the emphasis should shift to the evaluation of recurrent symptoms and prevention of restenosis. We discuss the methods used to assess the results of coronary angioplasty and suggest guidelines for managing patients after the procedure. [ABSTRACT FROM AUTHOR]

Coronary angiography and left ventriculography is commonly used to identify those patients with incomplete infarctions and therefore, a need for revascularization. The authors compared coronary angiography and left ventriculography with thalliumm 201 tomography using oral dipyridamole to identify patients with potential ischemia in the infarct zone indicating viable tissue. Forty-five patients (37 men, 8 women) with acute myocardial infarctions (29 anterior, 16 inferior) who received intravenous thrombolytic therapy were studied. On the basis of the left ventriculograms, only 16 patients were judged to have residual function in the infarct zone. Six of these patients had no thallium redistribution in the infarct zone, indicating lack of residual ischemia. Of the 29 patients with no residual function in the infarct zone, 18 had redistribution in the Infarct zone, suggesting residual ischemic myocardium and thus viable tissue. Among the 32 patients with open infarct vessels, 15 had no redistribution in the infarct zone, but of the remaining 13 patients with occluded infarct vessels, 9 had redistribution in the infarct zone indicating residual ischemia and thus viable tissue. The authors' data suggest that neither wall motion analysis by left ventriculography nor the angiographic status of the infarct vessel identifies those patients with residual ischemia as evidenced by thallium tomography using oral dipyridamole. [ABSTRACT FROM AUTHOR]

Editorial. Discusses a study which examined the extent of using thrombolytic therapy in patients with myocardial infarction. Characteristics of patients who were investigated; Implications for medical practice; Discussion on the benefits of thrombolytic therapy.

Background: Standardization of risk is critical in benchmarking and quality improvement efforts for percutaneous coronary interventions (PCIs). In 2018, the CathPCI Registry was updated to include additional variables to better classify higher-risk patients.Objectives: This study sought to develop a model for predicting in-hospital mortality risk following PCI incorporating these additional variables.Methods: Data from 706,263 PCIs performed between July 2018 and June 2019 at 1,608 sites were used to develop and validate a new full and pre-catheterization model to predict in-hospital mortality, and a simplified bedside risk score. The sample was randomly split into a development cohort (70%, n = 495,005) and a validation cohort (30%, n = 211,258). The authors created 1,000 bootstrapped samples of the development cohort and used stepwise selection logistic regression on each sample. The final model included variables that were selected in at least 70% of the bootstrapped samples and those identified a priori due to clinical relevance.Results: In-hospital mortality following PCI varied based on clinical presentation. Procedural urgency, cardiovascular instability, and level of consciousness after cardiac arrest were most predictive of in-hospital mortality. The full model performed well, with excellent discrimination (C-index: 0.943) in the validation cohort and good calibration across different clinical and procedural risk cohorts. The median hospital risk-standardized mortality rate was 1.9% and ranged from 1.1% to 3.3% (interquartile range: 1.7% to 2.1%).Conclusions: The risk of mortality following PCI can be predicted in contemporary practice by incorporating variables that reflect clinical acuity. This model, which includes data previously not captured, is a valid instrument for risk stratification and for quality improvement efforts. [ABSTRACT FROM AUTHOR]