Cardiovascular disease in Switzerland - health care, mortality and geographical pattern

SUMMARY Switzerland is facing an aging population and a growing amount of patients with chronic diseases. It is crucial to display health care processes and pathways, to identify inequalities and obstacles, and to point out possibilities for improvements of the Swiss health care system (e.g. increase efficiency). The introductory part of the thesis presents a brief description of the Swiss health care system, health services research and regional variation as well as an introduction of CVD and its epidemiological key figures, aetiology and treatments. This is followed by the description of the utilized methods and data, and the objectives of this thesis. The subsequent sections present the four articles included in this thesis. The first article focuses on a small area analysis on regional variation of avoidable hospitalisations in Switzerland including density of primary care physicians and specialists, rurality and hospital supply factors as explanatory variables in the analysis. Lower rates of avoidable hospitalisations were found in areas with very high supply of primary care physicians, increased avoidable hospitalisation rates in areas with more specialists and in areas with higher proportion of rural residents. The second article aims to examine whether emergency patients with acute ST-segment elevation myocardial infarction were adequately treated, i.e. according to the treatment guidelines, in Switzerland. Results show that older and female patients were less likely to receive revascularization which suggests that the treatment guidelines may not be uniformly applied in Switzerland. Similar to the first article, also in the third article a small area analysis was performed but this time investigating regional variation in costs at the end of life. Strongest associations of cost was found with cause of death, age and language region of the decedents. The strong spatial variation of costs could only partly be explained by the included covariates. Article four aims to examine the relationship of distance to different hospital types and mortality from AMI or stroke. We found that AMI mortality in the Swiss population 30 and older and stroke mortality in those 65 and above increased with distance to central and university hospitals, while adjusting for sociodemographic and economic characteristics of the population. The presentation of the four articles is followed by a discussion, which summarizes the main findings and the strengths and limitations of the presented articles. The thesis concludes with a discussion about the challenges for policy, practice and future research.

Molecular genetics of sudden cardiac death in small animals - A review

Sudden cardiac death in small animals is uncommon but often occurs due to cardiac conduction defects or myocardial diseases. Primary cardiac conduction defects are mainly caused by mutations in genes involved in impulse conduction processes (e.g., gapjunction genes and transcription factors) or repolarisation processes (e.g., ion-channel genes), whereas primary cardiomyopathies are mainly caused by defective force generation or force transmission due to gene mutations in either sarcomeric or cytoskeleton proteins. Although over 50 genes have been identified in humans directly or indirectly related to sudden cardiac death, no genetic aetiologies have been identified in small animals. Sudden cardiac deaths have been also reported in German Shepherds and Boxers. A better understanding of molecular genetic aetiologies for sudden cardiac death will be required for future study toward unveiling actiology in sudden cardiac death in small animals. (c) 2005 Elsevier Ltd. All rights reserved.

Simulation of Brugada syndrome using cellular and three-dimensional whole-heart modeling approaches

Brugada syndrome (BS) is a genetic disease identified by an abnormal electrocardiogram ( ECG) ( mainly abnormal ECGs associated with right bundle branch block and ST-elevation in right precordial leads). BS can lead to increased risk of sudden cardiac death. Experimental studies on human ventricular myocardium with BS have been limited due to difficulties in obtaining data. Thus, the use of computer simulation is an important alternative. Most previous BS simulations were based on animal heart cell models. However, due to species differences, the use of human heart cell models, especially a model with three-dimensional whole-heart anatomical structure, is needed. In this study, we developed a model of the human ventricular action potential (AP) based on refining the ten Tusscher et al (2004 Am. J. Physiol. Heart Circ. Physiol. 286 H1573 - 89) model to incorporate newly available experimental data of some major ionic currents of human ventricular myocytes. These modified channels include the L-type calcium current (ICaL), fast sodium current (I-Na), transient outward potassium current (I-to), rapidly and slowly delayed rectifier potassium currents (I-Kr and I-Ks) and inward rectifier potassium current (I-Ki). Transmural heterogeneity of APs for epicardial, endocardial and mid-myocardial (M) cells was simulated by varying the maximum conductance of IKs and Ito. The modified AP models were then used to simulate the effects of BS on cellular AP and body surface potentials using a three-dimensional dynamic heart - torso model. Our main findings are as follows. (1) BS has little effect on the AP of endocardial or mid-myocardial cells, but has a large impact on the AP of epicardial cells. (2) A likely region of BS with abnormal cell AP is near the right ventricular outflow track, and the resulting ST-segment elevation is located in the median precordium area. These simulation results are consistent with experimental findings reported in the literature. The model can reproduce a variety of electrophysiological behaviors and provides a good basis for understanding the genesis of abnormal ECG under the condition of BS disease.

External Validation of the ProACS Score for Risk Stratification of Patients with Acute Coronary Syndromes

INTRODUCTION: The ProACS risk score is an early and simple risk stratification score developed for all-cause in-hospital mortality in acute coronary syndromes (ACS) from a Portuguese nationwide ACS registry. Our center only recently participated in the registry and was not included in the cohort used for developing the score. Our objective was to perform an external validation of this risk score for short- and long-term follow-up. METHODS: Consecutive patients admitted to our center with ACS were included. Demographic and admission characteristics, as well as treatment and outcome data were collected. The ProACS risk score variables are age (≥72 years), systolic blood pressure (≤116 mmHg), Killip class (2/3 or 4) and ST-segment elevation. We calculated ProACS, Global Registry of Acute Coronary Events (GRACE) and Canada Acute Coronary Syndrome risk score (C-ACS) risk scores for each patient. RESULTS: A total of 3170 patients were included, with a mean age of 64±13 years, 62% with ST-segment elevation myocardial infarction. All-cause in-hospital mortality was 5.7% and 10.3% at one-year follow-up. The ProACS risk score showed good discriminative ability for all considered outcomes (area under the receiver operating characteristic curve >0.75) and a good fit, similar to C-ACS, but lower than the GRACE risk score and slightly lower than in the original development cohort. The ProACS risk score provided good differentiation between patients at low, intermediate and high mortality risk in both short- and long-term follow-up (p<0.001 for all comparisons). CONCLUSIONS: The ProACS score is valid in external cohorts for risk stratification for ACS. It can be applied very early, at the first medical contact, but should subsequently be complemented by the GRACE risk score.

Gender difference in the use of coronary interventions for patients with acute coronary syndrome: experience from a major metropolitan hospital in Melbourne, Australia

BACKGROUND: Literature suggests an ongoing gender disparity in the use of coronary angiography and subsequent interventions among patients with acute coronary syndrome (ACS). OBJECTIVES: The study aimed to examine gender differences in the use of coronary interventions amongst patients with acute coronary syndrome (ACS) admitted to a major metropolitan hospital in Melbourne during the period 2009-2012. METHODS: We undertook a retrospective analysis of a hospital database of 2096 ACS patients. ACS included unstable angina (UA), ST-segment-elevation myocardial infarction (STEMI) and non-STEMI (NSTEMI). RESULTS: The mean age of the patients was 64.3 years and 624 (30%) were women. Half of them were diagnosed as NSTEMI, 23% as STEMI and 25% as UA. Compared to men, women were older at admission, less likely to be diagnosed with STEMI and less likely to smoke. No gender difference was observed for severe co-morbidities or use of coronary angiography. Women diagnosed with STEMI were 39% less likely to receive an angioplasty stent (adjusted odds ratio 0.61, 95% confidence intervals 0.39-0.96) and 66% less likely to receive grafts (adjusted OR 0.34, 95% CIs 0.13-0.93). Women diagnosed with NSTEMI were 44% less likely to receive grafts (adjusted OR 0.56, 95% CIs 0.37-0.83). Younger women aged 35-49 years were less likely to receive an angioplasty stent, and older women >50 years were less likely to receive grafts. CONCLUSIONS: Adherence to guideline based treatment will help to ensure knowledge translation from guideline to practice. Further research investigating symptom presentation, use of non-invasive tests and medical management of ACS by gender may further explain gender difference for coronary interventions.

Gender differences in presentation, coronary intervention, and outcomes of 28,985 acute coronary syndrome patients in Victoria, Australia

BACKGROUND: Differences in demographics, presenting characteristics, and treatment of heart disease in women may contribute to adverse outcomes. The purpose of this paper was to describe gender differences in the epidemiology, treatment, and outcomes of all admissions for acute coronary syndrome (ACS) in Victoria that occurred between June 2007 and July 2009. METHODS: We undertook a retrospective cohort study of all patients admitted to Victorian hospitals with a first time diagnosis of ACS. Use of angiograms, percutaneous coronary intervention (PCI), coronary artery bypass graft (CABG), and adverse outcomes (death and/or unplanned readmission) were compared by gender and hierarchical logistic regression models were used to account for confounding variables. RESULTS: Of a total of 28,985 ACS patients, 10,455 (36%) were women. Compared with men, women were older (aged ≥75 years: 54% vs 31%; p < .001), more likely to present with multiple comorbidities (>1 comorbidity: 53% vs 46%; p < .001), and more likely to be diagnosed with non-ST-segment elevation ACS (86% vs 80%; p < .001). Women were less likely to receive coronary interventions (angiogram: adjusted odds ratio [aOR], 0.71; 95% CI, 0.66-0.75; PCI: aOR, 0.73; 95% CI, 0.66-0.80; CABG: aOR, 0.58; 95% CI, 0.53-0.64). Adverse outcomes were similar in women and men after accounting for confounding variables. CONCLUSIONS: Our results show that women in Victoria were less likely to receive coronary interventions after an admission for ACS. Clinicians should be wary of inherent gender bias in decisions to refer patients for angiography.

Long-term benefit of early pre-reperfusion metoprolol administration in patients with acute myocardial infarction: Results from the Metocard-CNIC trial (Effect of Metoprolol in Cardioprotection during an Acute Myocardial Infarction)

The goal of this trial was to study the long-term effects of intravenous (IV) metoprolol administration before reperfusion on left ventricular (LV) function and clinical events. Early IV metoprolol during ST-segment elevation myocardial infarction (STEMI) has been shown to reduce infarct size when used in conjunction with primary percutaneous coronary intervention (pPCI). The METOCARD-CNIC (Effect of Metoprolol in Cardioprotection During an Acute Myocardial Infarction) trial recruited 270 patients with Killip class ≤II anterior STEMI presenting early after symptom onset (<6 h) and randomized them to pre-reperfusion IV metoprolol or control group. Long-term magnetic resonance imaging (MRI) was performed on 202 patients (101 per group) 6 months after STEMI. Patients had a minimal 12-month clinical follow-up. Left ventricular ejection fraction (LVEF) at the 6 months MRI was higher after IV metoprolol (48.7 ± 9.9% vs. 45.0 ± 11.7% in control subjects; adjusted treatment effect 3.49%; 95% confidence interval [CI]: 0.44% to 6.55%; p = 0.025). The occurrence of severely depressed LVEF (≤35%) at 6 months was significantly lower in patients treated with IV metoprolol (11% vs. 27%, p = 0.006). The proportion of patients fulfilling Class I indications for an implantable cardioverter-defibrillator (ICD) was significantly lower in the IV metoprolol group (7% vs. 20%, p = 0.012). At a median follow-up of 2 years, occurrence of the pre-specified composite of death, heart failure admission, reinfarction, and malignant arrhythmias was 10.8% in the IV metoprolol group versus 18.3% in the control group, adjusted hazard ratio (HR): 0.55; 95% CI: 0.26 to 1.04; p = 0.065. Heart failure admission was significantly lower in the IV metoprolol group (HR: 0.32; 95% CI: 0.015 to 0.95; p = 0.046). In patients with anterior Killip class ≤II STEMI undergoing pPCI, early IV metoprolol before reperfusion resulted in higher long-term LVEF, reduced incidence of severe LV systolic dysfunction and ICD indications, and fewer heart failure admissions.

Impact of the timing of metoprolol administration during STEMI on infarct size and ventricular function

Pre-reperfusion administration of intravenous (IV) metoprolol reduces infarct size in ST-segment elevation myocardial infarction (STEMI). This study sought to determine how this cardioprotective effect is influenced by the timing of metoprolol therapy having either a long or short metoprolol bolus-to-reperfusion interval. We performed a post hoc analysis of the METOCARD-CNIC (effect of METOprolol of CARDioproteCtioN during an acute myocardial InfarCtion) trial, which randomized anterior STEMI patients to IV metoprolol or control before mechanical reperfusion. Treated patients were divided into short- and long-interval groups, split by the median time from 15 mg metoprolol bolus to reperfusion. We also performed a controlled validation study in 51 pigs subjected to 45 min ischemia/reperfusion. Pigs were allocated to IV metoprolol with a long (−25 min) or short (−5 min) pre-perfusion interval, IV metoprolol post-reperfusion (+60 min), or IV vehicle. Cardiac magnetic resonance (CMR) was performed in the acute and chronic phases in both clinical and experimental settings. For 218 patients (105 receiving IV metoprolol), the median time from 15 mg metoprolol bolus to reperfusion was 53 min. Compared with patients in the short-interval group, those with longer metoprolol exposure had smaller infarcts (22.9 g vs. 28.1 g; p = 0.06) and higher left ventricular ejection fraction (LVEF) (48.3% vs. 43.9%; p = 0.019) on day 5 CMR. These differences occurred despite total ischemic time being significantly longer in the long-interval group (214 min vs. 160 min; p < 0.001). There was no between-group difference in the time from symptom onset to metoprolol bolus. In the animal study, the long-interval group (IV metoprolol 25 min before reperfusion) had the smallest infarcts (day 7 CMR) and highest long-term LVEF (day 45 CMR). In anterior STEMI patients undergoing primary angioplasty, the sooner IV metoprolol is administered in the course of infarction, the smaller the infarct and the higher the LVEF. These hypothesis-generating clinical data are supported by a dedicated experimental large animal study.

Correlacion entre hemoglobina glicosilada con hallazgos sintax score ii en pacientes con sospecha clínica de enfermedad coronaria, hospitalizados en la unidad coronaria del hospital San José centro en enero a septiembre del año 2015

Se realiza un estudio de corte transversal en el periodo de enero a septiembre del año 2016 en la unidad coronaria del Hospital San José Centro de la Ciudad de Bogotá; en pacientes con sospecha de enfermedad coronaria (Síndrome coronario agudo y angina estable) y antecedente de Diabetes Mellitus Tipo 2, se recolectaron 42 pacientes con los criterios de inclusión a quienes se realizó angiografía coronaria como parte del protocolo de estudio y manejo de la unidad, el objetivo primario fue demostrar la posible correlación entre niveles de hemoglobina glicosilada y la escala de severidad SYNTAX Score I y II de enfermedad coronaria, como objetivos secundarios; caracterizar las variables sociodemográficas, comorbilidades y posible relación con el tipo de presentación de enfermedad coronaria. Como hallazgos relevantes no se encontró correlación importante ni significativa entre niveles de hemoglobina glicosilada y la escala Syntax score II ni Syntax score I, a pesar de que la mayoría de pacientes mostraban mal control crónico de su diabetes mellitus tipo 2, con niveles mayores > 7%, como hallazgo positivo se encontro asociación estadísticamente significativa con niveles de LDL y las diferentes formas de presentación de enfermedad coronaria, a mayor niveles de LDL mayor probabilidad de IAM e IAM con elevación del segmento ST. Se considera que con estudios multicentricos en diferentes ciudades y unidades de cuidado cardiovascular con diferentes niveles de riesgo, se podría demostrar la posible correlación entre niveles de hemoglobina glicosilada y los grados de severidad de enfermedad coronaria representados por las escalas Syntax score I y II.

BNP and Admission Glucose as In-Hospital Mortality Predictors in Non-ST Elevation Myocardial Infarction

Objectives. Admission hyperglycemia and B-type natriuretic peptide (BNP) are associated with mortality in acute coronary syndromes, but no study compares their prediction in-hospital death. Methods. Patients with non-ST-elevation myocardial infarction (NSTEMI), in-hospital mortality and two-year mortality or readmission were compared for area under the curve (AUC), sensitivity (SEN), specificity (SPE), positive predictive value (PPV), negative predictive value (NPV), and accuracy (ACC) of glycemia and BNP. Results. Respectively, AUC, SEN, SPE, PPV, NPV, and ACC for prediction of in-hospital mortality were 0.815, 71.4%, 84.3%, 26.3%, 97.4%, and 83.3% for glycemia = 200 mg/dL and 0.748, 71.4%, 68.5%, 15.2%, 96.8% and 68.7% for BNP = 300 pg/mL. AUC of glycemia was similar to BNP (P = 0.411). In multivariate analysis we found glycemia >= 200mg/dL related to in-hospital death (P = 0.004). No difference was found in two-year mortality or readmission in BNP or hyperglycemic subgroups. Conclusion. Hyperglycemia was an independent risk factor for in-hospital mortality in NSTEMI and had a good ROC curve level. Hyperglycemia and BNP, although poor in-hospital predictors of unfavorable events, were independent risk factors for death or length of stay >10 days. No relation was found between hyperglycemia or BNP and long-term events.

ST Elevation Myocardial Infarction in the elderly

Acute coronary syndromes (ACS) are the leading causes of death in the elderly. The suspicion and diagnosis of ACS in this age group is more difficult, since typical angina is less frequent. The morbidity and mortality is greater in older age patients presenting ACS. Despite the higher prevalence and greater risk, elderly patients are underrepresented in major clinical trials from which evidence based recommendations are formulated. The authors describe, in this article, the challenges in the diagnosis and management of ST elevation myocardial infarction in the elderly, and discuss the available evidence.

Asociación de la concentración de material particulado en Bogotá con infarto agudo de miocardio

Introducción: la contaminación atmosférica no solo tiene efectos sobre el sistema respiratorio sino también sobre el cardiovascular. El objetivo de este estudio es generar evidencia que permita establecer una asociación entre el infarto agudo del miocardio y la concentración de PM10 en el ambiente como un estudio preliminar para un grupo de pacientes en Bogotá. Metodología: la asociación entre la concentración del material particulado (en este caso PM10 medido en la estación más cercana del lugar reportado por el paciente) y el infarto agudo del miocardio se estableció utilizando el diseño case crossover. Se utilizó información de las historias clínicas de los pacientes con infarto agudo del miocardio que ingresaron al Servicio de Urgencias de la FSFB, y las concentraciones de PM10 medido en la estación más cercana al lugar de inicio de los síntomas de síndrome coronario agudo, reportado por el paciente. Resultados: se encontró que la asociación entre la concentración de PM10 y el diagnóstico de infarto agudo del miocardio es estadísticamente significativa teniendo en cuenta tres momentos de control: 2 horas antes del evento, 24 horas antes del evento y 48 horas antes del evento. Discusión: este estudio sugiere que las altas concentraciones de material particulado en el ambiente son un factor de riesgo para el desarrollo de infarto agudo del miocardio especialmente en personas con enfermedad coronaria subyacente. Con esta investigación se demuestra la importancia de generar acciones que disminuyan la contaminación de la ciudad y de esta forma proteger la salud de las personas.

Acute coronary syndromes: management and secondary prevention

Acute coronary syndromes represent a broad spectrum of ischemic myocardial events including unstable angina, non-ST elevation myocardial infarction and acute ST elevation myocardial infarction, which are associated with high morbidity and mortality. They constitute the most frequent cause of hospital admission related to cardiac disease. Early diagnosis and risk stratification are essential for initiation of optimal medical and invasive management. Therapeutic measures comprise aggressive antiplatelet, antithrombotic, and anti-ischemic agents. In addition, patients with high-risk features, notably positive troponin, ST segment changes and diabetes, benefit from an early invasive as compared to a conservative strategy. Importantly, lifestyle interventions, modification of the risk factor profile, and long-term medical treatment are of pivotal importance in reducing the long-term risk of recurrence.

Effects of coronary sinus occlusion on myocardial ischaemia in humans: role of coronary collateral function

OBJECTIVE This study tested the hypotheses that intermittent coronary sinus occlusion (iCSO) reduces myocardial ischaemia, and that the amount of ischaemia reduction is related to coronary collateral function. DESIGN Prospective case-control study with intraindividual comparison of myocardial ischaemia during two 2-min coronary artery balloon occlusions with and without simultaneous iCSO by a balloon-tipped catheter. SETTING University Hospital. PATIENTS 35 patients with chronic stable coronary artery disease. INTERVENTION 2-min iCSO. MAIN OUTCOME MEASURES Myocardial ischaemia as assessed by intracoronary (i.c.) ECG ST shift at 2 min of coronary artery balloon occlusion. Collateral flow index (CFI) without iCSO, that is, the ratio between mean distal coronary occlusive (Poccl) and mean aortic pressure (Pao) both minus central venous pressure. RESULTS I.c. ECG ST segment shift (elevation in all) at the end of the procedure with iCSO versus without iCSO was 1.33±1.25 mV versus 1.85±1.45 mV, p<0.0001. Regression analysis showed that the degree of i.c. ECG ST shift reduction during iCSO was related to CFI, best fitting a Lorentzian function (r(2)=0.61). Ischaemia reduction with iCSO was greatest at a CFI of 0.05-0.20, whereas in the low and high CFI range the effect of iCSO was absent. CONCLUSIONS ICSO reduces myocardial ischaemia in patients with chronic coronary artery disease. Ischaemia reduction by iCSO depends on coronary collateral function. A minimal degree of collateral function is necessary to render iCSO effective. ICSO cannot manifest an effect when collateral function prevents ischaemia in the first place.