Impact of weather and climate on the incidence of acute coronary syndromes

BACKGROUND: First investigations of the interactions between weather and the incidence of acute myocardial infarctions date back to 1938. The early observation of a higher incidence of myocardial infarctions in the cold season could be confirmed in very different geographical regions and cohorts. While the influence of seasonal variations on the incidence of myocardial infarctions has been extensively documented, the impact of individual meteorological parameters on the disease has so far not been investigated systematically. Hence the present study intended to assess the impact of the essential variables of weather and climate on the incidence of myocardial infarctions. METHODS: The daily incidence of myocardial infarctions was calculated from a national hospitalization survey. The hourly weather and climate data were provided by the database of the national weather forecast. The epidemiological and meteorological data were correlated by multivariate analysis based on a generalized linear model assuming a log-link-function and a Poisson distribution. RESULTS: High ambient pressure, high pressure gradients, and heavy wind activity were associated with an increase in the incidence of the totally 6560 hospitalizations for myocardial infarction irrespective of the geographical region. Snow- and rainfall had inconsistent effects. Temperature, Foehn, and lightning showed no statistically significant impact. CONCLUSIONS: Ambient pressure, pressure gradient, and wind activity had a statistical impact on the incidence of myocardial infarctions in Switzerland from 1990 to 1994. To establish a cause-and-effect relationship more data are needed on the interaction between the pathophysiological mechanisms of the acute coronary syndrome and weather and climate variables.

The impact of statin treatment on presentation mode and early outcomes in acute coronary syndromes

OBJECTIVES: The role of statin use in the treatment of acute coronary syndromes (ACS) is not clear. The aim of our study was to evaluate the role of statins in ACS. METHODS: Using data from the Acute Myocardial Infarction in Switzerland (AMIS Plus) Project, we compared the effects of chronic statin use, statin therapy after admission and no statin therapy on presentation mode and outcomes in ACS. RESULTS: Available data from the period 2001-2006 including 11,603 patients were analyzed. Major cardiac event rates and in-hospital mortality were more common in statin-naive patients compared to patients who received statins. CONCLUSIONS: Our results support the importance of statin treatment in ACS. Chronic statin therapy seems to alter the initial presentation of ACS but it is questionable whether it provides an additional effect on early outcomes compared to the establishment of statin therapy after admission in statin-naive patients.

Expected impact of applying new 2013 AHA/ACC cholesterol guidelines criteria on the recommended lipid target achievement after acute coronary syndromes.

BACKGROUND 2013 AHA/ACC guidelines on the treatment of cholesterol advised to tailor high-intensity statin after ACS, while previous ATP-III recommended titration of statin to reach low-density lipoprotein cholesterol (LDL-C) targets. We simulated the impact of this change of paradigm on the achievement of recommended targets. METHODS Among a prospective cohort study of consecutive patients hospitalized for ACS from 2009 to 2012 at four Swiss university hospitals, we analyzed 1602 patients who survived one year after recruitment. Targets based on the previous guidelines approach was defined as (1) achievement of LDL-C target < 1.8 mmol/l, (2) reduction of LDL-C ≥ 50% or (3) intensification of statin in patients who did not reach LDL-C targets. Targets based on the 2013 AHA/ACC guidelines approach was defined as the maximization of statin therapy at high-intensity in patients aged ≤75 years and moderate- or high-intensity statin in patients >75 years. RESULTS 1578 (99%) patients were prescribed statin at discharge, with 1120 (70%) at high-intensity. 1507 patients (94%) reported taking statin at one year, with 909 (57%) at high-intensity. Among 482 patients discharged with sub-maximal statin, intensification of statin was only observed in 109 patients (23%). 773 (47%) patients reached the previous LDL-C targets, while 1014 (63%) reached the 2013 AHA/ACC guidelines targetsone year after ACS (p value < 0.001). CONCLUSION The application of the new 2013 AHA/ACC guidelines criteria would substantially increase the proportion of patients achieving recommended lipid targets one year after ACS. Clinical trial number, NCT01075868.

Cellular actors, Toll-like receptors, and local cytokine profile in acute coronary syndromes

Inflammation plays a key role in acute coronary syndromes (ACS). Toll-like receptors (TLR) on leucocytes mediate inflammation and immune responses. We characterized leucocytes and TLR expression within coronary thrombi and compared cytokine levels from the site of coronary occlusion with aortic blood (AB) in ACS patients.

[A Swiss multicentric project to improve the prevention of cardiovascular event recurrence after acute coronary syndromes]

Recurrence of cardiovascular events and mortality remain high after acute coronary syndromes. A Swiss multicentric study, "Inflammation and acute coronary syndromes (ACS)--Novel strategies for prevention and clinical managements", is currently underway with the support of the Swiss National Science Foundation. The study includes a clinical research subproject of which the aim is to assess the impact of the ELIPS program (multi-dimEnsionaL prevention Program after acute coronary Syndrome) on the recurrence of cardiovascular events after an ACS. The basic research sub-projects aim to investigate novel cardiovascular risk biomarkers and genetic determinants of recurrence and to study the role of stem cells after an ACS. Another sub-project will evaluate intracoronary imaging techniques and the efficacy of different types of stents.

Presentation and outcome of patients with acute coronary syndromes in eastern Nepal

The burden of ischemic heart disease (IHD) in developing countries is on the rise, due to urbanisation, industrialisation and the low availability of evidence based therapies and interventions.

Diabetes and acute coronary syndromes

Diabetic patients with acute coronary syndromes (ACSs) are at a high risk for subsequent cardiovascular events but derive, at the same time, greater benefit from evidence-based therapy than non-diabetic individuals. State-of-the-art anti-thrombotic therapy includes a triple anti-platelet combination - aspirin, clopidogrel and glycoprotein (GP) IIb/IIIa receptor inhibitors - and unfractionated heparin or enoxaparin. For low- or medium-risk individuals, a treatment based on aspirin, clopidogrel and bivalirudin is a valuable alternative. Prasugrel, a new and more potent inhibitor of the platelet P2Y(12) receptor, has to be regarded as the most promising anti-thrombotic agent for diabetic patients with ACS. This agent may replace clopidogrel - and possibly GP IIb/IIIa inhibitors - in the future. In addition to aggressive anti-thrombotic therapy, diabetic patients should undergo systematic early invasive angiography if presenting with non-ST-segment elevation ACS, and immediate percutaneous coronary intervention if presenting with ST-segment elevation myocardial infarction. Indeed, the benefit derived from these strategies appears to be more pronounced in the diabetic population than in non-diabetic individuals. Despite the benefit, multiple surveys have demonstrated that, in the setting of ACS, diabetic patients receive evidence-based therapy less frequently than non-diabetic counterparts.

[Treatment of acute coronary syndromes]

This article reviews the diagnostic steps and risk stratification in acute coronary syndromes. Therapeutic measures according to risk stratification are discussed as well. The article also reviews quality assurance in Switzerland (AMIS Plus Registry). Potential future perspectives in the treatment of acute coronary syndromes are shown.

Stent thrombosis with ticagrelor versus clopidogrel in patients with acute coronary syndromes: an analysis from the prospective, randomized PLATO trial

BACKGROUND We aimed to describe the effects of ticagrelor versus clopidogrel on stent thrombosis in the Platelet Inhibition and Patient Outcomes (PLATO) trial. METHODS AND RESULTS Of 18 624 patients hospitalized for acute coronary syndromes, 11 289 (61%) had at least 1 intracoronary stent. Ticagrelor reduced stent thrombosis compared with clopidogrel across all definitions: definite, 1.37% (n=71) versus 1.93% (n=105; hazard ratio [HR], 0.67; 95% confidence interval [CI], 0.50-0.90; P=0.0091); definite or probable, 2.21% (n=118) versus 2.87% (n=157; HR, 0.75; 95% CI, 0.59-0.95; P=0.017); and definite, probable, and possible, 2.94% (n=154) versus 3.77 (n=201; HR, 0.77; 95% CI, 0.62-0.95). The reduction in definite stent thrombosis was consistent regardless of acute coronary syndrome type, presence of diabetes mellitus, stent type (drug-eluting or bare metal stent), CYP2C19 genetic status, loading dose of aspirin, dose of clopidogrel before randomization, and use of glycoprotein IIb/IIIa inhibitors at randomization. The reduction in stent thrombosis with ticagrelor was numerically greater for late (>30 days; HR, 0.48; 95% CI, 0.24-0.96) and subacute (4 hours-30 days; HR, 0.60; 95% CI, 0.39-0.93) compared with acute (<24 hours; HR, 0.94; 95% CI, 0.43-2.05) stent thrombosis or for patients compliant to therapy (ie, taking blinded study treatment ≥80% of the time) compared with less compliant patients. Randomization to ticagrelor was a strong independent inverse predictor of definite stent thrombosis (HR, 0.65; 95% CI, 0.48-0.88). CONCLUSION Ticagrelor compared with clopidogrel reduces the incidence of stent thrombosis in patients with acute coronary syndromes, with consistent benefit across a broad range of patient, stent, and treatment characteristics.

Differential healing response attributed to culprit lesions of patients with acute coronary syndromes and stable coronary artery after implantation of drug-eluting stents: An optical coherence tomography study

BACKGROUND Pathology studies have shown delayed arterial healing in culprit lesions of patients with acute coronary syndrome (ACS) compared with stable coronary artery disease (CAD) after placement of drug-eluting stents (DES). It is unknown whether similar differences exist in-vivo during long-term follow-up. Using optical coherence tomography (OCT), we assessed differences in arterial healing between patients with ACS and stable CAD five years after DES implantation. METHODS AND RESULTS A total of 88 patients comprised of 53 ACS lesions with 7864 struts and 35 stable lesions with 5298 struts were suitable for final OCT analysis five years after DES implantation. The analytical approach was based on a hierarchical Bayesian random-effects model. OCT endpoints were strut coverage, malapposition, protrusion, evaginations and cluster formation. Uncovered (1.7% vs. 0.7%, adjusted p=0.041) or protruding struts (0.50% vs. 0.13%, adjusted p=0.038) were more frequent among ACS compared with stable CAD lesions. A similar trend was observed for malapposed struts (1.33% vs. 0.45%, adj. p=0.072). Clusters of uncovered or malapposed/protruding struts were present in 34.0% of ACS and 14.1% of stable patients (adj. p=0.041). Coronary evaginations were more frequent in patients with ST-elevation myocardial infarction compared with stable CAD patients (0.16 vs. 0.13 per cross section, p=0.027). CONCLUSION Uncovered, malapposed, and protruding stent struts as well as clusters of delayed healing may be more frequent in culprit lesions of ACS compared with stable CAD patients late after DES implantation. Our observational findings suggest a differential healing response attributable to lesion characteristics of patients with ACS compared with stable CAD in-vivo.

Bivalirudin or Unfractionated Heparin in Acute Coronary Syndromes.

Background Conflicting evidence exists on the efficacy and safety of bivalirudin administered as part of percutaneous coronary intervention (PCI) in patients with an acute coronary syndrome. Methods We randomly assigned 7213 patients with an acute coronary syndrome for whom PCI was anticipated to receive either bivalirudin or unfractionated heparin. Patients in the bivalirudin group were subsequently randomly assigned to receive or not to receive a post-PCI bivalirudin infusion. Primary outcomes for the comparison between bivalirudin and heparin were the occurrence of major adverse cardiovascular events (a composite of death, myocardial infarction, or stroke) and net adverse clinical events (a composite of major bleeding or a major adverse cardiovascular event). The primary outcome for the comparison of a post-PCI bivalirudin infusion with no post-PCI infusion was a composite of urgent target-vessel revascularization, definite stent thrombosis, or net adverse clinical events. Results The rate of major adverse cardiovascular events was not significantly lower with bivalirudin than with heparin (10.3% and 10.9%, respectively; relative risk, 0.94; 95% confidence interval [CI], 0.81 to 1.09; P=0.44), nor was the rate of net adverse clinical events (11.2% and 12.4%, respectively; relative risk, 0.89; 95% CI, 0.78 to 1.03; P=0.12). Post-PCI bivalirudin infusion, as compared with no infusion, did not significantly decrease the rate of urgent target-vessel revascularization, definite stent thrombosis, or net adverse clinical events (11.0% and 11.9%, respectively; relative risk, 0.91; 95% CI, 0.74 to 1.11; P=0.34). Conclusions In patients with an acute coronary syndrome, the rates of major adverse cardiovascular events and net adverse clinical events were not significantly lower with bivalirudin than with unfractionated heparin. The rate of the composite of urgent target-vessel revascularization, definite stent thrombosis, or net adverse clinical events was not significantly lower with a post-PCI bivalirudin infusion than with no post-PCI infusion. (Funded by the Medicines Company and Terumo Medical; MATRIX ClinicalTrials.gov number, NCT01433627 .).

Prevalence and management of familial hypercholesterolaemia in patients with acute coronary syndromes.

AIMS We aimed to assess the prevalence and management of clinical familial hypercholesterolaemia (FH) among patients with acute coronary syndrome (ACS). METHODS AND RESULTS We studied 4778 patients with ACS from a multi-centre cohort study in Switzerland. Based on personal and familial history of premature cardiovascular disease and LDL-cholesterol levels, two validated algorithms for diagnosis of clinical FH were used: the Dutch Lipid Clinic Network algorithm to assess possible (score 3-5 points) or probable/definite FH (>5 points), and the Simon Broome Register algorithm to assess possible FH. At the time of hospitalization for ACS, 1.6% had probable/definite FH [95% confidence interval (CI) 1.3-2.0%, n = 78] and 17.8% possible FH (95% CI 16.8-18.9%, n = 852), respectively, according to the Dutch Lipid Clinic algorithm. The Simon Broome algorithm identified 5.4% (95% CI 4.8-6.1%, n = 259) patients with possible FH. Among 1451 young patients with premature ACS, the Dutch Lipid Clinic algorithm identified 70 (4.8%, 95% CI 3.8-6.1%) patients with probable/definite FH, and 684 (47.1%, 95% CI 44.6-49.7%) patients had possible FH. Excluding patients with secondary causes of dyslipidaemia such as alcohol consumption, acute renal failure, or hyperglycaemia did not change prevalence. One year after ACS, among 69 survivors with probable/definite FH and available follow-up information, 64.7% were using high-dose statins, 69.0% had decreased LDL-cholesterol from at least 50, and 4.6% had LDL-cholesterol ≤1.8 mmol/L. CONCLUSION A phenotypic diagnosis of possible FH is common in patients hospitalized with ACS, particularly among those with premature ACS. Optimizing long-term lipid treatment of patients with FH after ACS is required.

Prognostic value of PCSK9 levels in patients with acute coronary syndromes.

AIMS Proprotein convertase subtilisin kexin 9 (PCSK9) is an emerging target for the treatment of hypercholesterolaemia, but the clinical utility of PCSK9 levels to guide treatment is unknown. We aimed to prospectively assess the prognostic value of plasma PCSK9 levels in patients with acute coronary syndromes (ACS). METHODS AND RESULTS Plasma PCSK9 levels were measured in 2030 ACS patients undergoing coronary angiography in a Swiss prospective cohort. At 1 year, the association between PCSK9 tertiles and all-cause death was assessed adjusting for the Global Registry of Acute Coronary Events (GRACE) variables, as well as the achievement of LDL cholesterol targets of <1.8 mmol/L. Patients with higher PCSK9 levels at angiography were more likely to have clinical familial hypercholesterolaemia (rate ratio, RR 1.21, 95% confidence interval, CI 1.09-1.53), be treated with lipid-lowering therapy (RR 1.46, 95% CI 1.30-1.63), present with longer time interval of chest pain (RR 1.29, 95% CI 1.09-1.53) and higher C-reactive protein levels (RR 1.22, 95% CI 1.16-1.30). PCSK9 increased 12-24 h after ACS (374 ± 149 vs. 323 ± 134 ng/mL, P < 0.001). At 1 year follow-up, HRs for upper vs. lower PCSK9-level tertiles were 1.13 (95% CI 0.69-1.85) for all-cause death and remained similar after adjustment for the GRACE score. Patients with higher PCSK9 levels were less likely to reach the recommended LDL cholesterol targets (RR 0.81, 95% CI 0.66-0.99). CONCLUSION In ACS patients, high initial PCSK9 plasma levels were associated with inflammation in the acute phase and hypercholesterolaemia, but did not predict mortality at 1 year.

Reasons for discontinuation of recommended therapies according to the patients after acute coronary syndromes.

BACKGROUND The prescription of recommended medical therapies is a key factor to improve prognosis after acute coronary syndromes (ACS). However, reasons for cardiovascular therapies discontinuation after hospital discharge are poorly reported in previous studies. METHODS We enrolled 3055 consecutive patients hospitalized with a main diagnosis of ACS in four Swiss university hospitals with a prospective one-year follow-up. We assessed the self-reported use of recommended therapies and the reasons for medication discontinuation according to the patient interview performed at one-year follow-up. RESULTS 3014 (99.3%) patients were discharged with aspirin, 2983 (98.4%) with statin, 2464 (81.2%) with beta-blocker, 2738 (90.3%) with ACE inhibitors/ARB and 2597 (100%) with P2Y12 inhibitors if treated with coronary stent. At the one-year follow-up, the discontinuation percentages were 2.9% for aspirin, 6.6% for statin, 11.6% for beta-blocker, 15.1% for ACE inhibitor/ARB and 17.8% for P2Y12 inhibitors. Most patients reported having discontinued their medication based on their physicians' decision: 64 (2.1%) for aspirin, 82 (2.7%) for statin, 212 (8.6%) for beta-blocker, 251 (9.1% for ACE inhibitor/ARB) and 293 (11.4%) for P2Y12 inhibitors, while side effect, perception that medication was unnecessary and medication costs were uncommon reported reasons (<2%) according to the patients. CONCLUSIONS Discontinuation of recommended therapies after ACS differs according the class of medication with the lowest percentages for aspirin. According to patients, most stopped their cardiovascular medication based on their physician's decision, while spontaneous discontinuation was infrequent.