Prehospital diagnosis and triage of ST-elevation myocardial infarction by paramedics without advanced care training.

BACKGROUND: Prehospital triage of ST-elevation myocardial infarction (STEMI) for primary percutaneous coronary intervention (PCI) reduces treatment times. Prehospital triage and transport of STEMI patients have traditionally been undertaken in emergency medical service systems with Advanced Care Paramedics (ACPs). However, ACPs are not available in many regions. A pilot study was conducted to determine the feasibility of prehospital STEMI triage in a region with only Primary Care Paramedics. METHODS: Hemodynamically stable patients with chest pain and suspected STEMI were brought directly to a catheterization laboratory for primary PCI. End points included accuracy of prehospital STEMI identification, complications during transfer, and treatment times. RESULTS: One hundred thirty-four consecutive patients with suspected STEMI were triaged for primary PCI. Only 1 patient developed complications during transport (rapid atrial flutter) that required ACP skills. One hundred thirty-three patients underwent urgent angiography, and 105 patients underwent PCI. Based on physician interpretation of the prehospital electrocardiogram, there was agreement with triage decision for 121 (90%) of the 134 cases. The final diagnosis based on the angiogram and cardiac markers was true STEMI for 106 patients and false positive for 28 patients. The median first medical contact to balloon time was 91 (81-115) minutes. CONCLUSIONS: Hemodynamically stable patients with suspected STEMI can be safely and effectively transported directly for primary PCI by paramedics without advanced care training. Prehospital STEMI triage for primary PCI can be extended to regions that have few or no paramedics with advanced care training.

Elevated troponin-I after percutaneous coronary interventions: incidence and risk factors.

BACKGROUND: Percutaneous coronary interventions (PCIs) are often complicated by postprocedural myocardial necrosis as manifested by elevated cardiac markers. PURPOSE: To assess the incidence and risk factors of elevated troponin-I (TnI) after PCI. METHODS AND RESULTS: We performed a retrospective analysis on 522 PCI cases over a 1-year period at a single center. An elevated postprocedural TnI (>1.0 ng/ml) occurred in 213 patients (40.8%). Overall, glycoprotein (GP) IIb/IIIa inhibitors were used in 52% of cases. Baseline clinical characteristics were similar between the positive and the negative TnI groups. A univariate analysis revealed that patients with elevated TnI post-PCI had significantly more multivessel (28% vs. 15%, P = .001) and multilesion interventions (44% vs. 27%, P<.0001). The lesions were longer, more often angulated and involving bifurcations, and more complex in the TnI-positive group. Stent use and number of stents was higher in the TnI-positive group, and longer inflation times (>30 s) or higher inflation pressures (>14 atm) were used more often in the TnI-positive group. GP IIb/IIIa inhibitor use was higher in the TnI-positive group (61% vs. 45%, P = .0007). After multivariable analysis, independent predictors of elevated TnI after PCI included multilesion intervention, lesion length, lesion angulation, and GP IIb/IIIa inhibitor use. CONCLUSION: TnI is elevated in approximately 40% of cases after PCI. TnI is more likely to be elevated after intervention on multiple lesions, angulated or long lesions.

Six-month outcomes after single- and multi-lesion percutaneous coronary intervention: results from the ROSETTA registry.

BACKGROUND: The American College of Cardiology/American Heart Association exercise testing guidelines suggest that routine functional testing may benefit patients at high risk of restenosis, such as those undergoing multi-lesion percutaneous coronary intervention (PCI). OBJECTIVES: To compare the six-month post-PCI clinical and procedural outcomes in patients following single- and multi-lesion PCI, and to examine the use of routine functional testing (ie, in all patients) versus selective functional testing (ie, only in those with recurrent symptoms) following multi-lesion PCI. METHODS: Six-month outcomes among 562 patients after single-lesion PCI and 229 patients after multi-lesion PCI were examined. All patients were enrolled in the Routine versus Selective Exercise Treadmill Testing after Angioplasty (ROSETTA) registry, a prospective, multicentre registry examining the use of functional testing after successful PCI. RESULTS: For single- versus multi-lesion PCI patients, respectively, rates of death (1.8% versus 2.2%, P=0.7) and myocardial infarction (0.7% versus 2.6%, P=0.03) were low in both groups. Rates of unstable angina (12.0% versus 11.7%, P=0.9) and the composite clinical end point of death, myocardial infarction or unstable angina (13.5% versus 13.9%, P=0.9) were similar. Multi-lesion PCI patients had a higher number of repeat PCI procedures (6.6% versus 13.4%, P=0.02) but there was no difference in the rates of coronary artery bypass graft surgery (3.0% versus 2.6%, P=0.7). A routine functional testing strategy was used in 28.0% of single-lesion and 31.6% of multi-lesion patients. In a multivariate analysis of the multi-lesion patients, routine functional testing was not associated with a significant reduction in the composite clinical event rate (odds ratio 0.5, 95% CI 0.2 to 1.7, P=0.27). CONCLUSIONS: During the six-month period following successful PCI, clinical event rates were similar among patients undergoing single- or multi-lesion PCI. Routine functional testing was not associated with a statistically significant benefit in patients after multi-lesion PCI. However, additional study is required to better define the role of routine functional testing in this subgroup of patients.

Functional testing after coronary artery bypass graft surgery: a meta-analysis.

BACKGROUND: A number of studies have examined the diagnostic abilities of various functional tests to assess graft stenosis or the progression of coronary artery disease after coronary artery bypass graft (CABG) surgery. However, a meta-analysis of these studies has not been performed. OBJECTIVES: To pool the results of studies examining the diagnostic abilities of exercise treadmill testing (ETT), stress myocardial perfusion imaging and stress echocardiography to predict graft stenosis or progression of disease in the native circulation post-CABG. METHODS: A MEDLINE search was conducted to identify studies examining post-CABG functional testing for the diagnosis of graft stenosis or progression of native disease. Sensitivities and specificities of these studies were pooled, and predictive values and likelihood ratios were calculated. RESULTS: A pooled analysis demonstrates that for the identification of graft stenosis or progression of native disease, ETT alone has a sensitivity of 45% (95% CI 36% to 54%) and a specificity of 82% (95% CI 68% to 95%). The use of stress myocardial perfusion imaging increased the sensitivity to 68% (95% CI 51% to 86%) and specificity to 84% (95% CI 78% to 91%). The use of stress echocardiography also resulted in an increased sensitivity of 86% (95% CI 78% to 94%) and specificity of 90% (95% CI 84% to 95%). CONCLUSION: If post-CABG functional testing is performed, stress ventricular imaging is superior to ETT alone for the diagnosis of graft stenosis or progression of disease in the native vessels.