Prognostic performance of the IABP-SHOCK II Risk Score among cardiogenic shock subtypes in the critical care cardiology trials network registry.

BACKGROUND: Risk stratification has potential to guide triage and decision-making in cardiogenic shock (CS). We assessed the prognostic performance of the IABP-SHOCK II score, derived in Europe for acute myocardial infarct-related CS (AMI-CS), in a contemporary North American cohort, including different CS phenotypes. METHODS: The critical care cardiology trials network (CCCTN) coordinated by the TIMI study group is a multicenter network of cardiac intensive care units (CICU). Participating centers annually contribute ≥2 months of consecutive medical CICU admissions. The IABP-SHOCK II risk score includes age > 73 years, prior stroke, admission glucose > 191 mg/dl, creatinine > 1.5 mg/dl, lactate > 5 mmol/l, and post-PCI TIMI flow grade < 3. We assessed the risk score across various CS etiologies. RESULTS: Of 17,852 medical CICU admissions 5,340 patients across 35 sites were admitted with CS. In patients with AMI-CS (n = 912), the IABP-SHOCK II score predicted a >3-fold gradient in in-hospital mortality (low risk = 26.5%, intermediate risk = 52.2%, high risk = 77.5%, P < .0001; c-statistic = 0.67; Hosmer-Lemeshow P = .79). The score showed a similar gradient of in-hospital mortality in patients with non-AMI-related CS (n = 2,517, P < .0001) and mixed shock (n = 923, P < .001), as well as in left ventricular (<0.0001), right ventricular (P = .0163) or biventricular (<0.0001) CS. The correlation between the IABP-SHOCK II score and SOFA was moderate (r2 = 0.17) and the IABP-SHOCK II score revealed a significant risk gradient within each SCAI stage. CONCLUSIONS: In an unselected international multicenter registry of patients admitted with CS, the IABP- SHOCK II score only moderately predicted in-hospital mortality in a broad population of CS regardless of etiology or irrespective of right, left, or bi-ventricular involvement.

Prognostic implications of low level cardiac troponin elevation using high-sensitivity cardiac troponin T.

BACKGROUND: High-sensitivity cardiac troponin T (hsTnT) is used in many countries, but is not available in the United States. Prior evidence has been viewed as inconclusive as to whether low cardiac troponin T (cTnT) concentrations detected with hsTnT are prognostically meaningful compared with fourth-generation cTnT. HYPOTHESIS: The aim of this study was to assess the prognostic performance of low-level cTnT elevations using the hsTnT assay compared with the assay (fourth-generation) currently available in the United States. METHODS: We measured serum cTnT in 4160 patients with non-ST-elevation acute coronary syndrome using both the hsTnT and fourth-generation assays. Patients were stratified at the 99th percentile cut point for each assay. RESULTS: Patients with baseline hsTnT ≥14 ng/L (n = 3697) vs <14 ng/L were at higher 30-day risk of cardiovascular death (CVD) or myocardial infarction (MI) (9.1% vs 1.9%, P < 0.0001). After adjusting for all other elements of the Thrombolysis In Myocardial Infarction risk score, hsTnT ≥14 carried a 5.2-fold higher risk of CVD/MI (95% confidence interval [CI]: 2.6-10.1, P < 0.0001). Low levels of hsTnT (14-50 ng/L) also revealed increased risk (CVD/MI: 6.4%, P = 0.002). Importantly, patients with negative fourth-generation cTnT but positive hsTnT were at 4.5-times higher risk of CVD/MI (95% CI: 1.9-11.0, P = 0.0008) than patients with negative hsTnT. In contrast, patients with a negative hsTnT but positive fourth-generation cTnT result had a lower rate of CVD/MI than with a positive hsTnT (1.3% vs 8.2%, P = 0.0005). CONCLUSIONS: Low-level increases in cTnT detected using the hsTnT assay identified patients at a meaningfully higher risk and who might otherwise be missed, and improves upon risk stratification using the cTnT assay currently available in the United States.

Prognostic performance of a high-sensitivity cardiac troponin I assay in patients with non-ST-elevation acute coronary syndrome.

BACKGROUND: High-sensitivity assays for cardiac troponin enable more precise measurement of very low concentrations and improved diagnostic accuracy. However, the prognostic value of these measurements, particularly at low concentrations, is less well defined. METHODS: We evaluated the prognostic performance of a new high-sensitivity cardiac troponin I (hs-cTnI) assay (Abbott ARCHITECT) compared with the commercial fourth generation cTnT assay in 4695 patients with non-ST-segment elevation acute coronary syndromes (NSTE-ACS) from the EARLY-ACS (Early Glycoprotein IIb/IIIa Inhibition in NSTE-ACS) and SEPIA-ACS1-TIMI 42 (Otamixaban for the Treatment of Patients with NSTE-ACS) trials. The primary endpoint was cardiovascular death or new myocardial infarction (MI) at 30 days. Baseline cardiac troponin was categorized at the 99th percentile reference limit (26 ng/L for hs-cTnI; 10 ng/L for cTnT) and at sex-specific 99th percentiles for hs-cTnI. RESULTS: All patients at baseline had detectable hs-cTnI compared with 94.5% with detectable cTnT. With adjustment for all other elements of the TIMI risk score, patients with hs-cTnI ≥99th percentile had a 3.7-fold higher adjusted risk of cardiovascular death or MI at 30 days relative to patients with hs-cTnI <99th percentile (9.7% vs 3.0%; odds ratio, 3.7; 95% CI, 2.3-5.7; P < 0.001). Similarly, when stratified by categories of hs-cTnI, very low concentrations demonstrated a graded association with cardiovascular death or MI (P-trend < 0.001). Use of sex-specific cutpoints did not improve prognostic performance. Patients with negative fourth generation cTnT (<10 ng/L) but hs-cTnI ≥26 ng/L were at increased risk of cardiovascular death/MI compared to those with hs-cTnI <26 ng/L (9.2% vs 2.9%, P = 0.002). CONCLUSIONS: Application of this hs-cTnI assay identified a clinically relevant higher risk of recurrent events among patients with NSTE-ACS, even at very low troponin concentrations.

Organization and staffing practices in US cardiac intensive care units: a survey on behalf of the American Heart Association Writing Group on the Evolution of Critical Care Cardiology.

BACKGROUND: The cardiac intensive care unit (CICU) has evolved into a complex patient-care environment with escalating acuity and increasing utilization of advanced technologies. These changing demographics of care may require greater clinical expertise among physician providers. Despite these changes, little is known about present-day staffing practices in US CICUs. METHODS AND RESULTS: We conducted a survey of 178 medical directors of ICUs caring for cardiac patients to assess unit structure and physician staffing practices. Data were obtained from 123 CICUs (69% response rate) that were mostly from academic medical centres. A majority of hospitals utilized a dedicated CICU (68%) and approximately half of those hospitals employed a 'closed' unit model. In 46% of CICUs, an intensivist consult was available, but not routinely involved in care of critically ill cardiovascular patients, while 11% did not have a board-certified intensivist available for consultation. Most CICU directors (87%) surveyed agreed that a closed ICU structure provided better care than an open ICU and 81% of respondents identified an unmet need for cardiologists with critical care training. CONCLUSIONS: We report contemporary structural models and staffing practices in a sample of US ICUs caring for critically ill cardiovascular patients. Although most hospitals surveyed had dedicated CICUs, a minority of CICUs employed a 'closed' CICU model and few had routine intensivist staffing. Most CICU directors agree that there is a need for cardiologists with intensivist training and expertise. These survey data reveal potential areas for continued improvement in US CICU organizational structure and physician staffing.

Transcatheter aortic valve replacement: history and current status.

Despite the poor prognosis associated with severe, symptomatic aortic stenosis, treatment options were limited for a large subgroup of patients deemed high risk for surgical replacement. The introduction of transcatheter aortic valve replacement (TAVR) over the past 10 years marks a new and exciting era in the treatment of valvular disease in these high-risk and inoperable patients. In this review, we outline the historical development, key clinical trials, current outcomes and future directions of TAVR.