Incidence and characteristics of inappropriate and false-positive cardiac catheterization laboratory activations in a regional primary percutaneous coronary intervention program

BACKGROUND

The implementation of regional primary percutaneous coronary intervention (PCI) programs has been critical in achieving timely intervention in patients with ST-segment elevation myocardial infarction (STEMI). However, 1 consequence has been inappropriate and false-positive cardiac catheterization laboratory (CCL) activations where either angiography is cancelled or no culprit lesion is found, respectively.

METHODS

We performed a retrospective cohort study of 1,391 patients referred for primary PCI to a single academic center from November 2007 to August 2013. Our purpose was to determine the incidence and characteristics of inappropriate and false-positive CCL activations by emergency departments (EDs) or emergency medical services (EMS), and the effect of a quality improvement (QI) initiative to reduce such events implemented during this period.

RESULTS

During the study period, there were 37 (2.7%) inappropriate and 206 (14.8%) false-positive CCL activations. There was no difference between the ED and EMS rates of inappropriate activation (2.1% vs 3.8%, P = .06). Among patients who proceeded to angiography, the false-positive rate for ED CCL activation was 16.9% compared to 11.5% for EMS (P = .01). Although there was no difference comparing inappropriate activation or false-positive rates before and after the QI initiative (P = .22), we observed an encouraging year-to-year trend.

CONCLUSIONS

Emergency department activation of the CCL is associated with a higher false-positive rate than activation by EMS. Further QI efforts are required to improve communication between interventional cardiologists, emergency physicians, and paramedics to improve the specificity of CCL activation while taking care not to sacrifice sensitivity and rapidity of diagnosis.

Comparison of abciximab and eptifibatide on angiographic and clinical outcomes in rescue percutaneous coronary intervention for failed fibrinolytic therapy

BACKGROUND

Adjunctive administration of the glycoprotein IIb/IIIa platelet receptor antagonist (GPA), abciximab, improves outcomes in patients undergoing rescue percutaneous coronary intervention (PCI). However, it is unknown if other GPAs provide a similar benefit in this setting.

OBJECTIVE

We sought to compare angiographic and clinical outcomes of patients receiving abciximab or eptifibatide as an adjunct to rescue PCI.

METHODS

In this prospective, nonrandomized study, consecutive patients who underwent rescue PCI and received adjunctive preprocedural GPA comprised the study population. Thrombolysis in myocardial infarction (TIMI) flow, corrected TIMI frame count (CTFC) and myocardial blush grade (MBG) were determined before and immediately after rescue PCI. Residual ST-segment elevation at 90-120 minutes and peak creatine kinase (CK) values for 48 hours after PCI were recorded. Major adverse cardiac events (MACE) including death, reinfarction and target vessel revascularization (TVR) were determined at discharge, 1 and 6 months.

RESULTS

A total of 241 patients were included in the study. 162 patients received abciximab and 79 received eptifibatide. There were no differences in baseline clinical and angiographic characteristics between groups. Post-PCI TIMI flow was similar but post-PCI CTFC was significantly lower (17 +/- 10 vs. 22 +/- 18; p = 0.01) and post-PCI MBG significantly higher (2.8 +/- 0.5 vs. 2.6 +/- 0.6; p = 0.01) in the abciximab group. Patients in the abciximab group had less ST-segment elevation (1.0 +/- 0.9 vs. 1.5 +/- 1.0 mm; p = 0.003) and lower peak CK (2,484 +/- 2,176 vs. 2,650 +/- 2,798 U/L; p = 0.001) after PCI. On multivariate analyses, abciximab administration (OR = 0.50, CI = 0.26, 0.96; p = 0.03), pre-PCI TIMI 3 flow (OR = 0.22, CI = 0.05, 0.99; p = 0.04) and female gender (OR = 0.24, CI = 0.08, 0.66; p = 0.006) were positive and cardiogenic shock (OR = 2.76, CI = 1.16, 6.58; p = 0.02) was a negative predictor of normal epicardial perfusion post PCI. Abciximab administration (OR = 0.46, CI = 0.24, 0.87; p = 0.02) and pre-PCI CTFC < 25 (OR = 0.09, CI = 0.02, 0.31, 0.0001) were positive predictors and cardiogenic shock (OR = 3.96, CI = 1.55, 10.12; p = 0.004) was a negative predictor of normal myocardial perfusion post-PCI as determined by CTFC. Abciximab administration (OR = 0.31, CI = 0.15, 0.63; p = 0.001) and pre-PCI MBG 3 (OR = 0.07, CI = 0.02, 0.23; p < 0.0001) were positive predictors of normal myocardial perfusion post-PCI as determined by MBG. In-hospital, 1- and 6-month clinical events and MACE rates did not differ between groups.

CONCLUSIONS

In the setting of rescue PCI, adjunctive administration of abciximab resulted in greater improvement in angiographic and electrical estimates of myocardial perfusion and smaller infarct size compared to eptifibatide. These findings suggest that all GPA may not provide equal benefit in rescue PCI.

Reliability of computed tomography: correlation with neuropathologic findings

Findings on cranial computed tomography (CT) were correlated with autopsy findings in 58 cases with 129 lesions to determine CT reliability. When only CT scans of good quality were considered, there were no false positive cases. The number of false negative studies varied directly with lesion size: one of 42 lesions larger than 2.5 cm; four of 12 lesions between 1.5 and 2.5 cm; 12 of 15 between 0.5 and 1.5 cm; and all 21 of those smaller than 0.5 cm. Lesion size was undetermined in the remaining 18 casesbecause of the nature of the disease. While the series is small, these results suggest that the current detector threshold for CT may be in the range of 0.5-1.5 cm, although smaller lesions may be seen if there is substantial surrounding edema.