Retrospective description and analysis of consecutive catheterization laboratory ST-segment elevation myocardial infarction activations with proposal, rationale, and use of a new classification scheme.

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.

Effect of renal function on survival after implantable cardioverter defibrillator placement.

Implantable cardioverter defibrillators (ICDs) are effective at reducing arrhythmic death in patients with left ventricular dysfunction, but few studies have investigated the outcomes after ICD implantation in patients with chronic kidney disease (CKD). We conducted a 2-center retrospective study of 958 patients who had undergone ICD placement for primary prevention from the 2000 to 2006. The patients were stratified into 5 groups according to the CKD stage (stage 1, glomerular filtration [GFR] 90 to 120 ml/min; stage 2, GFR 60 to 89 ml/min; stage 3, GFR 30 to 59 ml/min; stage 4, GFR 15 to 29 ml/min; and stage 5, GFR 0 to 14 ml/min). The primary end point was death at 1 year. Of the 958 patients included in our analysis, 73 (7.6%) had died at 1 year. The mortality rate at 1 year increased with worsening CKD (1.8%, 5.3%, 9.0%, 22%, and 38% for stage 1 to 5, respectively, p <0.0001 for group). CKD was an independent predictor of mortality; hazard ratio 1.0, 1.075 (95% confidence interval 0.578 to 2.0), 1.372 (95% confidence interval 0.736 to 2.556), 3.092 (95% confidence interval 1.52 to 6.29), and 10.15 (95% confidence interval 4.25 to 24.23) for stage 1 to 5, respectively (p <0.0001 for group). Patients with CKD and left ventricular dysfunction have a poor prognosis despite ICD placement. The 1-year mortality increased as the renal function decreased. In conclusion, physicians should be cognizant of the prognosis when considering whether an ICD should be implanted in patients with CKD.