Daniel Lindholm

Improved Patient Survival Using a Modified Resuscitation Protocol for Out-of-Hospital Cardiac Arrest

Background— Cardiac arrest continues to have poor survival in the United States. Recent studies have questioned current practice in resuscitation. Our emergency medical services system made significant changes to the adult cardiac arrest resuscitation protocol, including minimizing chest compression interruptions, increasing the ratio of compressions to ventilation, deemphasizing or delaying intubation, and advocating chest compressions before initial countershock. Methods and Results— This retrospective observational cohort study reviewed all adult primary ventricular fibrillation and pulseless ventricular tachycardia cardiac arrests 36 months before and 12 months after the protocol change. Primary outcome was survival to discharge; secondary outcomes were return of spontaneous circulation and cerebral performance category. Survival of out-of-hospital arrest of presumed primary cardiac origin improved from 7.5% (82 of 1097) in the historical cohort to 13.9% (47 of 339) in the revised protocol cohort (odds ratio, 1.80; 95% confidence interval, 1.19 to 2.70). Similar increases in return of spontaneous circulation were achieved for the subset of witnessed cardiac arrest patients with initial rhythm of ventricular fibrillation from 37.8% (54 of 143) to 59.6% (34 of 57) (odds ratio, 2.44; 95% confidence interval, 1.24 to 4.80). Survival to hospital discharge also improved from an unadjusted survival rate of 22.4% (32 of 143) to 43.9% (25 of 57) (odds ratio, 2.71; 95% confidence interval, 1.34 to 1.59) with the protocol. Of the 25 survivors, 88% (n=22) had favorable cerebral performance categories on discharge. Conclusions— The changes to our prehospital protocol for adult cardiac arrest that optimized chest compressions and reduced disruptions increased the return of spontaneous circulation and survival to discharge in our patient population. These changes should be further evaluated for improving survival of out-of-hospital cardiac arrest patients.

Ticagrelor vs. clopidogrel in patients with non-ST-elevation acute coronary syndrome with or without revascularization: results from the PLATO trial

Aims The optimal platelet inhibition strategy for ACS patients managed without revascularization is unknown. We aimed to evaluate efficacy and safety of ticagrelor vs. clopidogrel in the non-ST-elevation acute coronary syndrome (NSTE-ACS) subgroup of the PLATO trial, in the total cohort, and in the subgroups managed with and without revascularization within 10 days of randomization. Methods and results We performed a retrospective analysis of the primary endpoint of cardiovascular death/myocardial infarction/stroke. Among 18 624 PLATO patients, 11 080 (59%) were categorized as NSTE-ACS at randomization. During the initial 10 days, 74% had angiography, 46% PCI, and 5% CABG. In NSTE-ACS patients, the primary endpoint was reduced with ticagrelor vs. clopidogrel [10.0 vs. 12.3%; hazard ratio (HR) 0.83; 95% confidence interval (CI) = 0.74–0.93], as was myocardial infarction (6.6 vs. 7.7%; HR 0.86; 95% CI = 0.74–0.99), cardiovascular death (3.7 vs. 4.9%; HR 0.77; 95% CI = 0.64–0.93), and all-cause death (4.3 vs. 5.8%; HR 0.76; 95% CI = 0.64–0.90). Major bleeding rate was similar between treatment groups (13.4 vs. 12.6%; HR 1.07; 95% CI = 0.95–1.19), but ticagrelor was associated with an increase in non-CABG major bleeding (4.8 vs. 3.8%; HR 1.28; 95% CI = 1.05–1.56). Within the first 10 days, 5366 (48.4%) patients were managed without revascularization. Regardless of revascularization or not, ticagrelor consistently reduced the primary outcome (HR 0.86 vs. 0.85, interaction P = 0.93), and all-cause death (HR 0.75 vs. 0.73, interaction P = 0.89) with no significant increase in overall major bleeding. Conclusion In patients with NSTE-ACS, benefit of ticagrelor over clopidogrel in reducing ischaemic events and total mortality was consistent with the overall PLATO trial, independent of actually performed revascularization during the initial 10 days.

Biomarkers in Relation to the Effects of Ticagrelor in Comparison With Clopidogrel in Non–ST-Elevation Acute Coronary Syndrome Patients Managed With or Without In-Hospital Revascularization A Substudy From the Prospective Randomized Platelet Inhibition and Patient Outcomes (PLATO) Trial

Background— Risk stratification and the use of specific biomarkers have been proposed for tailoring treatment in patients with non–ST-elevation acute coronary syndrome (NSTE-ACS). We investigated the prognostic importance of high-sensitivity troponin T (hs-TnT), N-terminal pro-brain natriuretic peptide (NT-proBNP), and growth differentiation factor-15 (GDF-15) in relation to randomized treatment (ticagrelor versus clopidogrel) and management strategy (with or without revascularization) in the NSTE-ACS subgroup of the Platelet Inhibition and Patient Outcomes (PLATO) trial. Methods and Results— Of 18 624 patients in the PLATO trial, 9946 had an entry diagnosis of NSTE-ACS and baseline blood samples available. During index hospitalization, 5357 were revascularized, and 4589 were managed without revascularization. Hs-TnT, NT-proBNP, and GDF-15 were determined and assessed according to predefined cutoff levels. Median follow-up was 9.1 months. Increasing levels of hs-TnT were associated with increasing risk of cardiovascular death, myocardial infarction, and stroke in medically managed patients (P<0.001), but not in those managed invasively. NT-proBNP and GDF-15 levels were associated with the same events independent of management strategy. Ticagrelor versus clopidogrel reduced the rate of cardiovascular death, myocardial infarction, and stroke in patients with NSTE-ACS and hs-TnT ≥14.0 ng/L in both invasively and noninvasively managed patients; in patients with hs-TnT <14.0 ng/L, there was no difference between ticagrelor and clopidogrel in the noninvasive group Conclusions— Hs-TnT, NT-proBNP, and GDF-15 are predictors of cardiovascular death, myocardial infarction, and stroke in patients with NSTE-ACS managed noninvasively, and NT-proBNP and GDF-15 also in those managed invasively. Elevated hs-TnT predicts substantial benefit of ticagrelor over clopidogrel both in invasively and noninvasively managed patients, but no apparent benefit was seen at normal hs-TnT. Clinical Trial Registration— URL:http://www.clinicaltrials.gov. Unique identifier: NCT00391872.

Biomarkers for risk stratification of patients with ST-elevation myocardial infarction treated with primary percutaneous coronary intervention: Insights from the Platelet Inhibition and Patient Outcomes trial

BACKGROUND The incremental prognostic value of admission measurements of biomarkers beyond clinical characteristics and extent of coronary artery disease (CAD) in patients treated with primary percutaneous coronary intervention (PPCI) for ST-elevation myocardial infarction (STEMI) is unclear. METHODS Centrally analyzed plasma for biomarker measurements was available in 5,385 of the STEMI patients treated with PPCI in the PLATO trial. Extent of CAD was graded by operators in association with PPCI. We evaluated the prognostic value of high-sensitivity cardiac troponin T, N-terminal pro-B-type natriuretic peptide (NT-proBNP), and growth differentiation factor 15 (GDF-15) beyond clinical characteristics and extent of CAD using Cox proportional hazards analyses, C-index, and net reclassification improvement (NRI). Outcomes were cardiovascular death (CVD) and spontaneous myocardial infarction (MI). RESULTS Angiographic data on extent of CAD improved the prediction of CVD compared to clinical risk factors alone, increasing the C-index from 0.760 to 0.778, total NRI of 0.31. Biomarker information provided additional prognostic value for CVD beyond clinical risk factors and extent of CAD, C-indices ranging from 0.792 to 0.795 for all biomarkers, but with a higher NRI for NT-proBNP. Extent of CAD and high-sensitivity cardiac troponin T were not associated with spontaneous MI. The prediction of spontaneous MI beyond clinical characteristics and extent of CAD (C-index 0.647) was improved by both NT-proBNP (C-index 0.663, NRI 0.22) and GDF-15 (C-index 0.652, NRI 0.05). CONCLUSIONS Biomarker measurement on admission is feasible and provides incremental risk stratification in patients with STEMI treated with PPCI, with NT-proBNP and GDF-15 being most valuable due to the association with both CVD and spontaneous MI.

Genome-wide association and Mendelian randomization study of NT-proBNP in patients with acute coronary syndrome

N-terminal pro-B-type natriuretic peptide (NT-proBNP) is a strong predictor of mortality in coronary artery disease and is widely employed as a prognostic biomarker. However, a causal relationship between NT-proBNP and clinical endpoints has not been established. We have performed a genome-wide association and Mendelian randomization study of NT-proBNP. We used a discovery set of 3740 patients from the PLATelet inhibition and patient Outcomes (PLATO) trial, which enrolled 18 624 patients with acute coronary syndrome (ACS). A further set of 5492 patients, from the same trial, was used for replication. Genetic variants at two novel loci (SLC39A8 and POC1B/GALNT4) were associated with NT-proBNP levels and replicated together with the previously known NPPB locus. The most significant SNP (rs198389, pooled P = 1.07 × 10(-15)) in NPPB interrupts an E-box consensus motif in the gene promoter. The association in SLC39A8 is driven by a deleterious variant (rs13107325, pooled P = 5.99 × 10(-10)), whereas the most significant SNP in POC1B/GALNT4 (rs11105306, pooled P = 1.02 × 10(-16)) is intronic. The SLC39A8 SNP was associated with higher risk of cardiovascular (CV) death (HR = 1.39, 95% CI: 1.08-1.79, P = 0.0095), but the other loci were not associated with clinical endpoints. We have identified two novel loci to be associated with NT-proBNP in patients with ACS. Only the SLC39A8 variant, but not the NPPB variant, was associated with a clinical endpoint. Due to pleotropic effects of SLC39A8, these results do not suggest that NT-proBNP levels have a direct effect on mortality in ACS patients. PLATO Clinical Trial Registration: www.clinicaltrials.gov; NCT00391872.

Environmental Factors Encountered During Out-of-Hospital Intubation Attempts

Objectives. Emergency medical services (EMS) literature has studied paramedic performance with endotracheal intubation; however, there are few data describing environmental differences between out-of-hospital andin-hospital providers during intubation attempts. The purpose of this study was to describe the environmental factors encountered by paramedics. Methods. Setting: Midwest, urban, public utility model, all–advanced life support (ALS) ambulance service with 85,000 calls and55,000 transports per year. Design: Prospective, observational study using a standardized data-collection tool completed on all adult cardiac arrest patients for whom intubation was attempted during the period from September 1, 2000, through September 1, 2004. Descriptive data including count andfrequency statistics of environmental factors were calculated. Results. There were 1,894 attempts on 1,396 patients during the study period; 236 (12.5%) attempts on 161 patients (11.5%) were removed from the analysis because of incomplete data, leaving 1,658 attempts on 1,235 patients. The intubation success rate was 85% (95% confidence interval [CI] 83, 97). Paramedics most frequently attempt intubation indoors (1,239, 75%), prefer to kneel at the patients head (899, 54%), encounter significant scene distractions (340, 20%), have optimal lighting (1,271, 77%), but frequently have suboptimal space (655, 40%). Patients are most often supine (1,653, 99%). Conclusions. The out-of-hospital intubation environment is significantly different from that of in-hospital providers. Paramedics frequently have a poor physical operating environment andencounter significant distractions while trying to perform endotracheal intubation. Future studies should analyze the association of these factors with intubation success.

The Association of Dispatch Prioritization andPatient Acuity

Introduction. EMS systems use call prioritization to distinguish between high andlow acuity patients, better use resources, andset system response times. Previous research focused on patient condition; however, recent research has reviewed patient acuity as an important maker for system response. Our objective was to analyze any trend between priority dispatch determinant codes andusing a red lights andsiren (RLS) transport from the scene. Methods. Retrospective cohort observational study of 9-1-1 calls received in CY 2003. Chi-square analysis for trend andodds ratios with 95% CI were calculated to evaluate the differences in proportions of patients being transported RLS from the scene according to determinant level, p < 0.05 was considered significant. Results. There was significant heterogeneity among the determinant cohorts (chi-square = 204.477, p < 0.001, 5 df). Further analysis showed absolute andproportional increases in RLS transport from the scene with increasing determinant level. The three lowest determinant levels were low risk (OR 0.13, 0.49, and0.58), andthe two highest determinant levels had significant risk for RLS transport (OR 1.63, 32.11). Conclusions. Patients had increasing likelihood of being transported by RLS from the scene with increasing determinant level. Calls with the two highest determinant levels were at significant risk of being transported RLS from the scene.

Real-life clinical outcomes with everolimus eluting platinum chromium stent with an abluminal biodegradable polymer in patients from the Swedish Coronary Angiography and Angioplasty Registry (SCAAR)

No previous studies have evaluated the performance of the Synergy stent in a large real‐life population.

Biomarkers and Coronary Lesions Predict Outcomes after Revascularization in Non–ST-Elevation Acute Coronary Syndrome

BACKGROUND Risk stratification in non-ST-elevation acute coronary syndrome (NSTE-ACS) is currently mainly based on clinical characteristics. With routine invasive management, angiography findings and biomarkers are available and may improve prognostication. We aimed to assess if adding biomarkers [high-sensitivity cardiac troponin T (cTnT-hs), N-terminal probrain-type natriuretic peptide (NT-proBNP), growth differentiation factor 15 (GDF-15)] and extent of coronary artery disease (CAD) might improve prognostication in revascularized patients with NSTE-ACS. METHODS In the PLATO (Platelet Inhibition and Patient Outcomes) trial, 5174 NSTE-ACS patients underwent initial angiography and revascularization and had cTnT-hs, NT-proBNP, and GDF-15 measured. Cox models were developed adding extent of CAD and biomarker levels to established clinical risk variables for the composite of cardiovascular death (CVD)/spontaneous myocardial infarction (MI), and CVD alone. Models were compared using c-statistic and net reclassification improvement (NRI). RESULTS For the composite end point and CVD, prognostication improved when adding extent of CAD, NT-proBNP, and GDF-15 to clinical variables (c-statistic 0.685 and 0.805, respectively, for full model vs 0.649 and 0.760 for clinical model). cTnT-hs did not contribute to prognostication. In the full model (clinical variables, extent of CAD, all biomarkers), hazard ratios (95% CI) per standard deviation increase were for cTnT-hs 0.93(0.81-1.05), NT-proBNP 1.32(1.13-1.53), GDF-15 1.20(1.07-1.36) for the composite end point, driven by prediction of CVD by NT-proBNP and GDF-15. For spontaneous MI, there was an association with NT-proBNP or GDF-15, but not with cTnT-hs. CONCLUSIONS In revascularized patients with NSTE-ACS, the extent of CAD and concentrations of NT-proBNP and GDF-15 independently improve prognostication of CVD/spontaneous MI and CVD alone. This information may be useful for selection of patients who might benefit from more intense and/or prolonged antithrombotic treatment. ClinicalTrials.gov Identifier: NCT00391872.

TICAGRELOR VERSUS CLOPIDOGREL IN PATIENTS WITH NON-ST-ELEVATION ACUTE CORONARY SYNDROME: RESULTS FROM THE PLATO TRIAL

Ticagrelor versus clopidogrel in patients with non-st-elevation acute coronary syndrome : results from the PLATO trial