Gérald Vanzetto

Inappropriate dispatcher decision for emergency medical service users with acute myocardial infarction.

OBJECTIVESnCurrent guidelines recommend utilization of prehospital emergency medical services (EMSs) by patients with ST-elevation myocardial infarction (STEMI). The aims of this study were to estimate the percentage of inappropriate initial dispatcher decisions and determine their impact on delays in reperfusion therapy for EMS users with STEMI.nnnMETHODSnAs part of a prospective regional registry of patients with STEMI, we analyzed the original data for 245 patients who called a university hospital-affiliated EMS call center in France. The primary study outcome was time to reperfusion therapy calculated from the documented date and time of the first patient call.nnnRESULTSnThe initial EMS dispatchers decision was appropriate (ie, dispatching a mobile intensive care unit staffed by an emergency or critical care physician) for 171 (70%) patients and inappropriate for 74 (30%) patients. Inappropriate decisions included referring the patient to a family physician (n = 59), providing medical advice (n = 9), and dispatching an ambulance (n = 6). Inappropriate initial decisions resulted in increased median time to reperfusion for 140 patients receiving fibrinolysis (95 vs 53 minutes; P < .001) and 91 patients undergoing primary percutaneous coronary intervention (170 vs 107 minutes; P < .001). In-hospital mortality was not different between the 2 study groups (6.8% vs 9.9%; P = .42).nnnCONCLUSIONnThe initial dispatchers decision is inappropriate for 30% of EMS users with STEMI and results in substantial delays in time to reperfusion therapy. Accuracy of telephone triage should be improved for patients who activate EMSs in response to symptoms suggestive of acute coronary syndrome.

The favorable price evolution between bare metal stents and drug eluting stents increases the cost effectiveness of drug eluting stents.

AIMSnWe aimed to assess the cost effectiveness of the sirolimus-eluting stent (SES) in diabetic and non-diabetic patients vs. bare metal stents (BMS).nnnMETHODSnEVASTENT was a matched cohort registry of patients undergoing revascularization exclusively with SES; for each diabetic patient (db+) included, stratified according to single (SVD) or multiple (MVD) vessel disease, a non-diabetic patient (db-) was subsequently included. Efficacy, safety and cost data were obtained from the SES database, and then data from the BMS group were derived by using an original method of transition probabilities of events (Markov model and Monte Carlo simulations) if BMS had been implanted in the same patient, over a 3-year time period. Sensitivity analysis was performed by varying the price difference between BMS and SES from 2008 to 2012.nnnRESULTSnIn this study, 1731 patients were included with 97% complete follow-up at 3-years. In 2008, compared to BMS the SES was cost effective only in MVD db+ (7494€ per avoided revascularization (PAR) vs. >10,000€ in other groups). In 2012, after a reduction in the price difference between SES and BMS, SES were cost effective in MVD db+ (-891), SVD db+ (3519), MVD db- (3050), and SVD db- (6329) patients. Otherwise, the cardiovascular mortality rate was higher (p<0.0001) in MVD db+ than in SVD db+, MVD db- and SVD db-.nnnCONCLUSIONnThe SES is now cost effective in diabetic and non-diabetic patients, after a favorable price evolution between drug eluting and bare metal stents.

Stress thallium-201/rest technetium-99m sequential dual-isotope high-speed myocardial perfusion imaging validation versus invasive coronary angiography

BackgroundRecent advances in nuclear myocardial perfusion imaging (MPI) have made it possible to develop a dual-isotope protocol for high-speed acquisition with image quality and radiation delivery comparable to that obtained with conventional single isotope protocols. So far, no study has compared dual-isotope high-speed MPI to invasive coronary angiography (ICA) in a large cohort using a Cadmium-zinc-telluride SPECT system.MethodsOver a 1-year period (May 2011 to April 2012), 1366 patients underwent dual-isotope high-speed MPI. Patients with ICA within 3xa0months after dual-isotope high-speed MPI were included together with patients with a low likelihood of coronary artery disease (CAD) in order to assess normalcy rate. Global summed stress score (SSS) and summed rest score (SRS) were calculated, and ICA results were analyzed independently. The main end point was a patient-based assessment of the diagnostic performance of dual-isotope high-speed MPI in detecting or ruling out significant CAD (>70% reduction in lumen diameter).ResultsInclusion criteria were fulfilled for 214 patients (143 men; age 60xa0±xa014xa0years; ICA, nxa0=xa0104; low likelihood for CAD, nxa0=xa0110). An exercise stress test was performed in 62% of patients and a pharmacological stress test was performed with either dipyridamole (32%) or dobutamine (6%). Average examination duration was 22.4xa0±xa04.5xa0minutes. Mean SSS, SRS, and SDS were 8.0xa0±xa04.9, 3.1xa0±xa04.3, and 5.0xa0±xa03.2, respectively. Prevalence of angiographic CAD was 75%. ICA detected stenosis in the left main trunk, left anterior descending artery, left circumflex artery, and right coronary artery in 4, 33, 31, and 42 patients, respectively. Sensitivity of dual-isotope high-speed MPI was 94%, normalcy rate was 92%, and accuracy was 83% for detecting CAD.ConclusionDual-isotope high-speed MPI is reliable at detecting or ruling out CAD. NCT01785589

Effect of Coronary Thrombus Aspiration During Primary Percutaneous Coronary Intervention on One-Year Survival (from the FAST-MI 2010 Registry)

Results from randomized trials evaluating thrombus aspiration (TA) in patients with ST-elevation myocardial infarction (STEMI) are conflicting. We assessed 1-year survival in STEMI patients participating in the French Registry of Acute ST-Elevation and non-ST-Elevation Myocardial Infarction (FAST-MI) 2010 according to the use of TA during primary percutaneous coronary intervention (PCI). FAST-MI 2010 is a nationwide French registry that included 4,169 patients with acute myocardial infarction at the end of 2010 in 213 centers. Of those, 2,087 patients had STEMI, of whom 1,538 had primary PCI, with TA used in 671 (44%). Patients with TA were younger (61 ± 13.5 vs 63 ± 14 years), with a similar risk score of the Global Registry of Acute Coronary Events (140 ± 31 vs 143 ± 34) and a shorter median time from symptom onset (245 vs 285 minutes); location of acute myocardial infarction, history of myocardial infarction, PCI, or coronary artery bypass surgery did not differ significantly. Thirty-day mortality was 2.1% versus 2.1% (adjusted p = 0.18), and the rate of 1-year survival was 95.5% versus 94.8%. Using fully adjusted Cox multivariate analysis, hazard ratio for 1-year death was 1.13 (95% confidence interval 0.66 to 1.94). After propensity score matching (480 patients per group), 1-year survival was also similar with both strategies. In a real-world setting of patients admitted with STEMI, the use of TA during primary PCI was not associated with improved 1-year survival.

Efficacy and safety of glycoprotein IIb/IIIa receptor antagonists for patients undergoing percutaneous coronary intervention within twelve hours of fibrinolysis†

Objective: To compare clinical outcomes between glycoprotein IIb/IIIa receptor antagonist recipients and nonrecipients who underwent percutaneous coronary intervention (PCI) within 12 hr of fibrinolysis. Background: Despite limited evidence, glycoprotein IIb/IIIa receptor antagonists are widely used in ST‐elevation myocardial infarction (STEMI) patients undergoing routine early or rescue PCI after fibrinolysis. Methods: We evaluated 87 and 556 glycoprotein IIb/IIIa receptor antagonist recipients and nonrecipients enrolled in a regional registry of STEMI between October 2002 and December 2005. The primary efficacy endpoint was a composite of death from any cause, reinfarction, and stroke at 1 year of follow‐up. The primary safety endpoint was the rate of in‐hospital major bleeding that was not related to coronary artery bypass grafting. Results: The primary efficacy endpoint occurred in 12% (10 of 81) and 13% (72 of 525) of glycoprotein IIb/IIIa receptor antagonist recipients and nonrecipients, respectively (P = 0.74). The corresponding rates of major bleeding during index hospitalization were 4.8% (4 of 84) and 5.1% (28 of 544) (P = 0.88), respectively. Two glycoprotein IIb/IIIa receptor antagonist recipients and five nonrecipients experienced intracranial hemorrhage. After adjusting for propensity score, the odds of primary efficacy (odds ratio, 0.79; 95% confidence interval, 0.34–1.83) and safety (odds ratio, 0.75; 95% confidence interval, 0.22–2.62) endpoints did not differ according to the use of glycoprotein IIb/IIIa receptor antagonists. Conclusion: In this observational cohort study of unselected patients with STEMI, the administration of glycoprotein IIb/IIIa receptor antagonists provided no additional benefit to PCI performed within 12 hr of fibrinolysis, nor did it compromise patient safety.

Stent-Related Cardiac Events Beyond Three Years After Implantation of the Sirolimus-Eluting Stent (from the EVASTENT Patients)

The frequency of very late stent thrombosis (VLST) up to 3 years after sirolimus-eluting stent implantation is 0.5% to 0.6%/year but incertitude remains about the frequency of VLAST after 3 years. Diabetic (db+) and nondiabetic (db-) patients with or without multiple diseased vessels included in the EVASTENT matched-cohort registry were followed up to 6 years after stent implantation. Long-term follow-up was obtained for 1,564 of the 1,731 included patients. All-cause deaths (including cancer and complications of diabetes) occurred at steady rates of 2.5%/year up to 3 years and 1.2%/year after 3 years (difference not significant). In contrast, VLST (any Academic Research Consortium definition) was only 0.18%/year (95% confidence interval 0.08 to 0.39) after 3 years versus 0.63%/year (confidence interval 0.41 to 0.98) from 1 year to 3 years (p = 0.03). Target lesion revascularization rates were also lower after 3 years than before 3 years (1.9% vs 7%, p ≤ 0.01) with 66% of revascularization procedures after 3 years being for nontarget lesions. Six-year all-cause death and cardiac death cumulative rates were higher in db+ than in db- patients. However, after 3 years compared to before 3 years, no differences between db+ and db- patients were observed for target lesion revascularization and ST rates. It is noteworthy that 51% of patients continued to be on clopidogrel therapy nearly 6 years after receiving ≥ 1 sirolimus-eluting stent. In conclusion, all-cause deaths continued at a steady rate over 6 years. However, cardiac deaths and very VLST leveled out beyond 3 years.

Platelet hyperactivity during exercise leading to iterative coronary stent thrombosis: clinical implications

Exercise may induce platelet activation in spite of using antiplatelet treatment. We present a case where the initial acute coronary syndrome and the iterative stent thrombosis always occurred after intense and prolonged physical effort. For this patient the at rest response to platelet inhibition with antiplatelet treatments was assessed as adequate, but after exercise the patient developed platelet activation which could be the trigger of his stent thrombosis.

Equivocal usefulness of FDG for the noninvasive imaging of abdominal aortic aneurysms

Abdominal aortic aneurysms (AAA) usually progress asymp-tomatically and are undetected until rupture occurs. Onceruptured, the mortality rate of AAA is about 80 %. Amongall patients with ruptured AAA, about one-third die withoutreachinghospital,andaboutanotherquarterreachhospitalbutdie prior to surgical intervention. Among the remaining pa-tients (about 40 %) surviving AAA rupture long enough tobenefit from surgical intervention, the perioperative mortalityhas historically reached about 50 % [1], a value that hashowever recently decreased owing to the introduction ofendovascular repair [2]. On the other hand, elective AAArepair has a much lower in-hospital mortality rate, with re-cently reported values of 1.3 % and 4.7 % for endovascularand open surgical repair, respectively [3], thereby stronglyemphasizingtheneedforscreeningandidentificationofthosepatients with prone-to-rupture AAA.The crude estimate of AAA diameter remains the mostwidely used predictive risk factor for AAA rupture and thesole therapeutic management criterion. Indeed, in both the2014EuropeanSocietyofCardiologyandthe2011AmericanCollege of Cardiology/American Heart Association guide-lines, aortic repair is a class I indication if the AAA diameterexceeds55mm[4,5].However,thelimitationsofthisparam-eter are well acknowledged, and it is therefore unanimouslyagreed that a more robust noninvasive predictor of the indi-vidual riskofAAA rupture is required. Althoughbeing muchless documented than atherogenesis, the current knowledgeregarding the pathophysiology of AAA indicates that parietalinflammation, matrix degradation and smooth muscle cellapoptosis are required for AAA pathogenesis [6]. FDG hasbeen suggested as a potentially useful agent for the molecularimaging of vascular inflammation due to the elevated carbo-hydratemetabolismofextravasatedinflammatorycells[7].Assuch, the tracer has been extensively evaluated in both theexperimentalandclinicalsettingsforthenoninvasiveimagingof inflammatory processes in vulnerable atherosclerotic le-sions as well as in AAA.In the multicentre study by Barwick and colleagues pub-lished in this issue of the European Journal of Nuclear Med-icine&MolecularImaging[8],theauthorsusedPETimagingof FDG uptake to retrospectively compare the metabolicactivity in the abdominal aortic wall of 151 patients withAAA (mean aortic diameter, 50±13 mm) with that of 159individuals with no AAA (mean aortic diameter, 21±3 mm)and matched for age, sex, diabetes, smoking status, statin useand indication for PET/CT. This cohort is the largest so farused for the comparison of FDG uptake between AAA andnormal vessels in well-matched patients. FDG uptake wasanalysed by semiquantitative visual scoring as well as quan-titatively using SUVmax and target to background ratiosutilizing mediastinal blood pool or descending thoracic aortaactivities for normalization.Althoughthe retrospective natureand the design of the study limit the conclusions that can bedrawn with respect to the potential of FDG for predictingAAA growth or rupture, the results unequivocally show thatthere was no correlation between AAA size and FDG uptakeand that there was no statistically significant difference inFDG uptake between AAA and normal abdominal aortas.The study by Barwick et al. therefore joins the ranks ofthose suggesting the suboptimal usefulness of FDG for AAAevaluation, which face the ranks of previously publishedstudies that reached opposite conclusions by suggesting the

Assessment of non-reperfused and reperfused myocardial infarction using diffusible or deposited radiolabelled perfusion imaging agents

PurposeIncomplete microvascular reperfusion is often observed in patients undergoing thrombolytic therapy or angioplasty for acute myocardial infarction and has important prognostic implications. We compared the myocardial uptake of diffusible (201Tl) and deposited (99mTcN-NOET) perfusion imaging agents in the setting of experimental infarction.MethodsRats were subjected to permanent coronary occlusion (OCC, n=10) or to 45-min occlusion and reperfusion (REP, n=17). Seven days later, the tracers were co-injected and the animals were euthanised 15xa0min (all ten rats in the OCC group and 12 rats in the REP group) or 120xa0min (five rats from the REP group, euthanised at this time point to evaluate any redistribution of the tracers: REP-RED group) afterwards. Infarct size determination and 99mTcN-NOET/201Tl ex vivo imaging were performed. Regional flow and tissue oedema were quantified using radioactive microspheres and 99mTc-DTPA, respectively.Results99mTcN-NOET and 201Tl defect magnitudes were similar in OCC animals (0.11±0.01 vs 0.13±0.01). In REP animals, 201Tl defect magnitude (0.25±0.02) was significantly lower than the magnitude of 99mTcN-NOET and flow defects (0.14±0.03 and 0.17±0.01, respectively; p<0.05), despite the lack of 201Tl redistribution (REP-RED animals). 99mTc-DTPA indicated the presence of oedema in the reperfused area. Blood distribution studies showed that, unlike 99mTcN-NOET, 201Tl plasma activity was mostly unbound to plasma proteins.Conclusion99mTcN-NOET and 201Tl delineated the non-viable area in chronic non-reperfused and reperfused myocardial infarction. The significantly decreased 201Tl defect in reperfused infarction was likely due to partial diffusion of the tracer from the plasma into the oedema present in the infarcted area. Deposited perfusion tracers might be better suited than diffusible agents for the assessment of regional flow following reperfusion of myocardial infarction.

Myocardium segmentation on 3D spect images

This paper presents a segmentation process of the myocardium, endocardium and epicardium surfaces of the heart from 3D SPECT images to compute a heterogeneity index. This index represents the distribution of the activity in the myocardium. Because of the low resolution of SPECT images, the thickness of the myocardium is 1 to 4 voxels and a sub-voxel accuracy is therefore needed. The segmentation process is based on the minimization of an energy by dynamic programming after a coarse segmentation to define the center surface of the myocardium. A Gaussian mixture is fitted on the data to ensure subvoxel accuracy. The heterogeneity index is compared to the reference index on 58 SPECT images and the segmentation is visually validated on 300 SPECT images by a clinician.