Increase in out-of-hospital cardiac arrest attended by the medical mobile intensive care units, but not myocardial infarction, during the 2003 heat wave in Paris, France.

OBJECTIVES: To address the association between the 2003 heat wave in Paris (France) and the occurrence of out-of-hospital cardiac arrest. DESIGN: : An analysis of the interventions of the medical mobile intensive care units of the City of Paris for out-of-hospital cardiac arrest and prehospital myocardial infarctions, which were routinely and prospectively computerized from January 1, 2000, to December 31, 2005. SETTING: City of Paris, France. PATIENTS: Participants were consecutive victims of witnessed out-of-hospital cardiac arrest due to heart disease and of ST-segment elevation myocardial infarction (STEMI) aged >or=18 yrs, who were attended by the medical mobile intensive care units (MICUs) of the City of Paris from January 1, 2000, to December 31, 2005. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The numbers of out-of-hospital cardiac arrests and of STEMIs during the 2003 heat wave period (August 1 to August 14) were compared (Poisson regression analysis) with the respective average numbers during the same period in reference years 2000-2002 and 2004-2005 when there was no heat wave. Mean ages of the 3049 patients experiencing out-of-hospital cardiac arrest and the 2767 patients experiencing STEMI attended by the MICUs during the study period were 64.3 +/- 18.0 and 65.2 +/- 15.4, respectively, and two thirds were males. During the heat wave period, the number of out-of-hospital cardiac arrests (n = 40) increased 2.5-fold compared with the reference periods (n = 81 for 5 yrs; p < .001); this corresponded to an estimated relative rates of out-of-hospital cardiac arrests of 2.34 (95% confidence interval, 1.60-3.41), after adjustment for age and for gender. This increase was observed in both genders (p for interaction with gender = .48) but only in those who were aged >or=60 yrs (p for interaction with age = .005). No variation was found for myocardial infarctions during heat wave. CONCLUSIONS: These data suggest that a heat wave may be associated with an increased risk of sudden cardiac death in the population.

Impact of prehospital thrombolysis for acute myocardial infarction on 1-year outcome: results from the French Nationwide USIC 2000 Registry.

BACKGROUND: Limited data are available on the impact of prehospital thrombolysis (PHT) in the "real-world" setting. METHODS AND RESULTS: Of 443 intensive care units in France, 369 (83%) prospectively collected all cases of infarction (< or =48 hours of symptom onset) in November 2000; 1922 patients (median age, 67 years; 73% men) with ST-segment-elevation infarction were included, of whom 180 (9%) received intravenous thrombolysis before hospital admission (PHT). Patients with PHT were younger than those with in-hospital thrombolysis, primary percutaneous interventions, or no reperfusion therapy. Median time from symptom onset to hospital admission was 3.6 hours for PHT, 3.5 hours for in-hospital lysis, 3.2 hours for primary percutaneous interventions, and 12 hours for no reperfusion therapy. In-hospital death was 3.3% for PHT, 8.0% for in-hospital lysis, 6.7% for primary percutaneous interventions, and 12.2% for no reperfusion therapy. One-year survival was 94%, 89%, 89%, and 79%, respectively. In a multivariate analysis of predictors of 1-year survival, PHT was associated with a 0.49 relative risk of death (95% CI, 0.24 to 1.00; P=0.05). When the analysis was limited to patients receiving reperfusion therapy, the relative risk of death for PHT was 0.52 (95% CI, 0.25 to 1.08; P=0.08). In patients with PHT admitted in < or =3.5 hours, in-hospital mortality was 0% and 1-year survival was 99%. CONCLUSIONS: The 1-year outcome of patients treated with PHT compares favorably with that of patients treated with other modes of reperfusion therapy; this favorable trend persists after multivariate adjustment. Patients with PHT admitted very early have a very high 1-year survival rate.

Management of acute dyspnoea: use and feasibility of brain natriuretic peptide (BNP) assay in the prehospital setting.

STUDY OBJECTIVES: Diagnosis of acute left ventricular failure (LVF) is often difficult in the prehospital setting. Brain natriuretic peptide (BNP) is a marker of LVF. The object of this study was to evaluate the feasibility of BNP measurement during the prehospital management of patients with dyspnoea. DESIGN: Prospective feasibility study, in the Paris Emergency Medical Service (SAMU). PATIENTS: All patients, aged 50 years and over, presenting with acute dyspnoea were included in the study, unless the dyspnoea was of circumstantial origin. Bedside BNP assays were conducted in parallel with the usual clinical management. For each patient, three diagnoses (cardiac, respiratory or uncertain) were established: firstly, according to the usual clinical criteria (diagnosis 1); secondly (diagnosis 2) according to the result of BNP measurement. When the diagnoses 1 and 2 were not in agreement, patients were entered into a category labeled "diagnostic correction". RESULTS: Fifty-two patients were included in the study. Twenty-one patients had clinically obvious LVF (diagnosis 1' = cardiac). For seven other patients, the clinical variables suggested a respiratory cause (diagnosis 1 = respiratory). For 24 patients dyspnoea was due to a non-identified cause (diagnosis 1 = uncertain). BNP levels were measured in 51 out of 52 patients (one failure). Only nine patients had a BNP level lower than the threshold value of 100 pg ml(-1). In 71% the diagnosis 1 was corrected after BNP estimation. Only two of 27 patients with marked bronchospasm had a BNP level lower than 100 pg ml(-1). CONCLUSION: Estimation of BNP is both feasible and easy in prehospital care, and can confirm the cardiac origins of atypical acute dyspnoea. In elderly patients LVF appears to be clinically underestimated. BNP assay may produce improvements in prehospital management of patients with dyspnoea.

Diagnosis and management of out-of-hospital cardiac arrest secondary to coronary artery spasm.

OBJECTIVE: The clinical features of coronary artery spasm as a cause of cardiac arrest were determined in a prospective study on out-of-hospital cardiac arrest (OHCA). METHODS: Coronary angiography was performed at admission in 300 consecutive patients with no obvious non-cardiac cause of OHCA. In survivors with no or minimal coronary artery stenosis, a second angiography with provocation test and electrophysiological testing were performed at 1 month. RESULTS: Spasm was demonstrated in ten patients. Diagnosis was based upon (1) spontaneous spasm on the admission angiogram (3 patients), (2) transient significative ST-segment elevation at follow-up in patients with no or non-significant coronary artery lesions (4 patients) and (3) spasm during the 1 month provocation test (3 patients). Six patients survived at 1 month; spasm occurred during a new provocation test in five despite treatment with high dosage calcium channel blockers leading to coronary stenting in two, an internal cardiovertor defibrillator in one, and increased drug therapy with prolonged hospitalization in the remainder. At a mean follow-up of 55+/-27 months, no recurrent cardiac arrest occurred. CONCLUSION: Systematic coronary angiograms and provocation tests in survivors of OHCA allow prompt diagnosis of coronary artery spasm. Residual spasm despite treatment with calcium channel blockers is frequent. Therapy should therefore be guided by repetitive provocation tests, and seems to avoid recurrence of cardiac arrest.