Warm winter is associated with low incidence of ST elevation myocardial infarctions and less frequent acute coronary angiographies in an alpine country.

BACKGROUND: Weather conditions influence symptoms in chronic stable coronary artery disease (CAD). Whether the ongoing climate change, with continuous and rapid temperature increases, also has an impact on the incidence and outcome of non-ST elevation (NSTEMI) and ST elevation (STEMI) myocardial infarctions referred for acute coronary angiography (CA) is less clear. METHODS: According to weather data from the Institute of Meteorology and Geophysics, Innsbruck University, the 2005/2006 winter was very cold (CW) and the 2006/2007 winter extraordinarily warm (WW). As the overall invasive management of patients with acute coronary syndromes did not change substantially within these winters, we compared patients referred for acute CA suffering an acute STEMI or NSTEMI, their risk factors and in-hospital mortality rates between these two consecutive winters. RESULTS: As expected, the average temperature was lower (- 1.6 vs. + 5.9°C; p < 0.001) and humidity was higher (82 vs. 79%; p < 0.012) in CW compared to WW, with no significant differences in other weather conditions (rainfall: 59 vs. 39 days; sunshine: 3.9 vs. 4.3 h/day; air pressure: 713.04 vs. 713.76 hPa). There were no differences in the number of overall CA (987 vs. 983) between these two winters, whereas the number of acute CA (12.9 vs. 10.4% of overall CA; p = 0.046) and the diagnosis of STEMI as an indication of acute CA (74.0% vs. 62.7%; p = 0.046) were higher in CW. Furthermore, patients in CW were younger (58.2 ± 12.4 vs. 61.7 ± 11.7 years; p < 0.03), had higher LDL cholesterol (134.8 ± 44.6 vs. 116.7 ± 36.0 mg/dl; p < 0.003) and were less frequently hypertensives (52.8 vs. 70.6%; p < 0.01). Other traditional risk factors were not different between WW and CW. In addition, there were no differences in in-hospital mortality rates in invasively diagnosed CAD, patients' nationalities (Austrians: 78.0 vs. 77.5%) and time from pain to arrival in the cath lab in STEMI patients (3.9 ± 3.5 vs. 3.8 ± 3.1 h). CONCLUSION: The average temperature increase of 7.5°C from the cold to the warm winter was associated with a decrease in acute coronary angiographies, in particular due to a lower incidence of STEMI referred for primary percutaneous intervention.

Safety and efficacy of femoral artery closure with the FemoSeal(R) device after coronary angiography using a 7 French sheath.

Post-cardiac catheterization femoral artery hemostasis can be accomplished with several mechanisms, including the FemoSeal® hemostasis device which has been designed and approved for closure of 6 French (F) arterial puncture sites. The aim of this study was to investigate whether the FemoSeal® vascular closure device can effectively and safely seal 7F arterial puncture sites after diagnostic and interventional cardiac catheterizations. Femoral artery puncture sites of 50 consecutive patients undergoing cardiac catheterization were closed with the FemoSeal® vascular closure device, according to the manufacturer's instructions. Efficacy endpoints were time to hemostasis and successful ambulation. Safety endpoints included bleeding complications, vessel occlusion and pseudoaneurysms. Mean time to hemostasis was 57.8±26.3 seconds (0-125 seconds). Hemostasis was achieved in 100 percent of the 50 patients. One patient suffered minor bleeding the next day, i.e. local hematoma. This clinical study demonstrates that the FemoSeal® vascular closure device, initially approved for closure of 6F arterial puncture sites, shows promising efficacy and safety to seal a larger (7F) femoral arterial puncture sites after diagnostic and interventional cardiac catheterizations.

Occurrence of acute myocardial infarction in winter tourists: data from a retrospective questionnaire.

BACKGROUND: Every year millions of tourists spend their vacation in Tyrol, Austria during the winter season. They often perform sports at high altitudes and at low temperatures, factors that might cause acute myocardial infarction (AMI). This study aimed to evaluate the relationship of first physical activity and the onset of AMI in winter tourists. METHODS: We carried out a retrospective analysis of consecutive patients admitted to the Department of Internal Medicine III at the Medical University of Innsbruck with the diagnosis of an AMI between 2006 and 2010. We identified 172 patients as potential candidates for the questionnaire. We successfully contacted 110 patients (mean age: 60 ± 10 years). The location of visit, duration of stay, time of arrival, first sportive activity and onset of symptoms were assessed. RESULTS: During the first 2 days of physical activity , 56% of AMIs occurred. In tourists who suffered AMI during, or within 1 h after cessation of activity (52%), the mean time from the start of the activity to the onset of symptoms was 2.0 ± 1.7 h. 56% of patients performed less than 2.5 h of sport per week before their vacation and 70% had ≥2 cardiovascular risk factors. Although the mean planned vacation time was 8.3 ± 3.7 days, 39% of the patients suffered from AMI on the day of arrival or the day after. CONCLUSION: The majority of AMIs in winter tourists happens within the first 2 days after arrival and within the first 2 days of physical activity.

Limited utilities of N-terminal pro B-type natriuretic peptide and other newer risk markers compared with traditional risk factors for prediction of significant angiographic lesions in stable coronary artery disease.

OBJECTIVE: To investigate the usefulness of N-terminal pro-brain natriuretic peptide (NT-proBNP) as a predictive marker for angiographically significant coronary artery disease (CAD) and CAD severity compared with other newer biochemical risk markers and classic risk factors in patients with clinically suspected CAD. DESIGN: Cross-sectional evaluation of NT-proBNP in a large consecutive series of patients without a history of myocardial infarction referred for elective coronary angiography (CAG) between March 2004 and January 2005. The value of NT-proBNP for predicting CAD was assessed and compared with high sensitivity C-reactive protein (hs-CRP), gamma-glutamyltransferase (GGT) and traditional risk factors. SETTING: Tertiary care centre, Department of Cardiology, Innsbruck Medical University, Austria. PATIENTS: 561 men and 287 women aged between 20-86 years (median 65 years). INTERVENTIONS: None. MAIN OUTCOME MEASURES: Association of NT-proBNP with the severity of CAD, left ventricular dysfunction and comparison of predictive values of NT-proBNP, hs-CRP, GGT and traditional CAD risk factors. RESULTS: Of all tested newer biochemical risk markers NT-proBNP performed best. In a multinomial logistic regression model NT-proBNP but not hs-CRP or GGT was significantly associated with three-vessel CAD adjusted for age, sex, ventricular, renal function and classic risk factors (odds ratio = 1.667; 95% CI 1.003 to 2.772; p = 0.049). However, NT-proBNP had no additive predictive value to traditional cardiovascular risk factors for the prediction of angiographically significant CAD in a binary logistic regression model. CONCLUSIONS: The predictive value of NT-proBNP for CAD severity is better than that of hs-CRP or GGT. However, NT-proBNP is also of limited value compared with traditional risk factors for predicting significant CAD.

High-density lipoprotein cholesterol, C-reactive protein, and prevalence and severity of coronary artery disease in 5641 consecutive patients undergoing coronary angiography.

BACKGROUND: Although high-density lipoprotein cholesterol (HDL-C) and C-reactive protein (CRP) are well-established predictors for future cardiovascular events, little information is available regarding their correlation with the prevalence and severity of angiographically evaluated coronary artery disease (CAD). MATERIAL AND METHODS: Five thousand six hundred forty-one consecutive patients undergoing coronary angiography for the evaluation of CAD were analysed. Cardiovascular risk factors were assessed by routine blood chemistry and questionnaire. CAD severity was graded by visual estimation of lumen diameter stenosis with significant stenoses defined as lumen diameter reduction of >or= 70%. Coronary angiograms were graded as one-, two- or three-vessel disease, as nonsignificant CAD (lumen irregularities < 70%) or non-CAD. RESULTS: HDL-C (60.3 +/- 18.5 vs. 51.9 +/- 15.3 mg dL(-1); P < 0.001) was higher and CRP was lower (0.65 +/- 1.68 vs. 1.02 +/- 2.38 mg dL(-1); P < 0.001) in non-CAD (n = 1517) compared to overall CAD patients (n = 4124). CAD patients were older (65.2 +/- 10.5 years vs. 59.9 +/- 11.4 years), more often diabetics (19.2% vs. 10.6%) and hypertensives (79.2% vs. 66.0%) and included more smokers (18.8% vs. 16.5%) (all P < 0.005). Low-density lipoprotein cholesterol (124.5 +/- 38.3 vs. 126.0 +/- 36.3 mg dL(-1); P = NS) was similar in overall CAD and non-CAD patients with more statin users (43.4% vs. 27.9%; P < 0.001) among CAD patients. Comparing non-CAD with different CAD severities using analysis of variance, results did not change substantially. In a multivariate analysis, HDL-C and CRP remained independently associated with the prevalence of CAD. In addition, HDL-C is also a potent predictor for the severity of CAD. CONCLUSIONS: In this large consecutive patient cohort, HDL-C and CRP are independently associated with the prevalence of CAD. In this analysis, HDL-C is an even stronger predictor for CAD than some other major classical risk factors.

Impact of exercise capacity on myocardial high-energy phosphate metabolism.

31-Phosphorous magnetic resonance spectroscopy (31P MRS) is a unique tool to investigate IN VIVO high-energy phosphates (HEP) in the human heart. We hypothesized that physical capacity may be associated with myocardial HEP status. Healthy, male volunteers (n = 105, mean age 51 +/- 7 years) underwent bicycle ergometry with a stepwise increasing workload to determine maximal working capacity (MWC). Heart rate (HR) and blood pressure (BP) were measured continuously during exercise and 4 minutes of recovery. Further 31-Phosphorous 2-dimensional chemical shift imaging (31P 2D CSI) MRS was performed to assess myocardial HEP metabolism by determining phosphocreatinine to beta-ATP ratios (PCr/b-ATP) using a 1.5 tesla scanner. Volunteers with MWC > 230 Watt had significantly higher PCr/b-ATP ratios than those with MWC < 200 Watt (1.93 +/- 0.36 vs. 1.59 +/- 0.35; p < 0.001). Additionally, those with a recovery systolic (S)BP < 195 mmHg had significantly higher ratios than those with a recovery SBP > 195 mmHg (1.74 +/- 0.3 vs. 1.51 +/- 0.2; p < 0.05). We observed a linear correlation between the PCr/b-ATP ratio and MWC (r = 0.411; p < 0.001) and recovery SBP (r = - 0.290; p < 0.01). After statistical correction for age, these correlations remained significant. In this study, we observed a correlation of parameters of physical fitness determined by bicycle exercise testing and cardiac PCr/b-ATP ratios.

Risk factor profile for sudden cardiac death during mountain hiking.

Mountain hiking is associated with a death rate of about 4 deaths per 100,000 hikers annually. About 50 % of all fatalities during mountain hiking are sudden cardiac deaths (SCDs). But there are only few data available regarding risk factors and triggers associated with SCD during mountain hiking. Thus, a case-control analysis between persons who died suddenly during mountain hiking and randomly selected controls was carried out. Risk factor profiles of 179 males over the age of 34 who suffered SCD during mountain hiking were compared to those of 537 matched controls. Hikers who died suddenly during mountain hiking were much more likely to have had a prior MI (17% vs. 0.9%; p < 0.001), known coronary artery disease (CAD) without prior MI (17 % vs. 4%; p < 0.001), diabetes (6% vs. 1 %; p < 0.001), hypercholesterolemia (54 % vs. 20%; p < 0.001), and were less engaged in regular mountain sports activities (31% vs. 58%; p < 0.001) compared to hikers from the control group. Based on the reported relationship between traditional risk factors and coronary plaque morphology, acute plaque rupture with thrombus formation and subsequent lethal arrhythmias may be assumed to be a dominant mechanism precipitating SCD during hiking. In contrast, in skiers especially non-occlusive plaques may precipitate ischemia leading to an imbalance between oxygen demand and supply and subsequent lethal arrhythmias. As preventive measures recommended to hikers at risk, adaptation to regular mountain sports activities by an adequate training program and pharmacological interventions, e.g. lipid lowering drugs, aspirin, and beta-blockers, should be considered.

ADMA is independently related to flow-mediated vasodilation in subjects at low cardiovascular risk.

BACKGROUND: Increased plasma concentrations of asymmetric dimethylarginine (ADMA) contribute to impair endothelial function in patients with established cardiovascular disease (CVD) and/or individuals with clinical syndromes known to increase CVD. However, the impact of ADMA on endothelial function in apparently healthy individuals has not been determined. MATERIALS AND METHODS: To address this issue, we measured endothelial-dependent vasodilatation in response to forearm ischaemia (flow-mediated vasodilatation, FMD) in 111 non-smoking, healthy volunteers with low CVD risk by the Framingham risk equation. Measurements were also made of multiple anthropometric, metabolic, and dynamic variables related to FMD. l-arginine and its methylated derivates (ADMA and SDMA) were quantified by high-liquid pressure chromatography. RESULTS: After adjustment by gender, lower values for FMD were significantly associated with increases in plasma ADMA concentrations (anova linear trend by FMD tertiles, P < 0.05) as well as in brachial artery diameter (partial r = -0.352, P = 0.001), body mass index (-0.337, P = 0.001), fasting insulin (-0.368, P < 0.001) and high-sensitivity C-reactive protein (-0.283, P = 0.007) plasma concentrations, and with decreased HDL cholesterol (0.233, P = 0.026). Multiple linear regression analysis indicated that the only statistically significant predictors of FMD were brachial artery diameter (P < 0.001), ADMA (P < 0.05) and fasting plasma insulin (P < 0.001) concentrations. CONCLUSIONS: In conclusion, a significant relationship between increases in plasma ADMA concentration and lower values of FMD is not limited to patients with clinical syndromes related to CVD, but can also be seen in healthy subjects at low global CVD risk.

Evaluation of transient apical ballooning with cardiac magnetic resonance imaging and 31-phosphorous magnetic resonance spectroscopy.

Apical ballooning is an increasingly reported transient cardiomyopathy with yet unknown origin. In this study 2 cases of apical ballooning are described in whom we used a combined approach of cardiac magnetic resonance imaging (CMR) and 31-Phosphorous magnetic resonance spectroscopy (31P MRS). Electrocardiogram showed ST abnormalities and cardiac serum markers were mildly elevated, but CAG demonstrated smooth coronary arteries. Cine-CMR revealed severe apical akinesia and significantly decreased ejection fraction. Furthermore we detected reduced myocardial phosphocreatine to beta-ATP (PCr/b-ATP) ratios during the first week of acute disease. After 1 week we observed an improvement of PCr/b-ATP ratios by 68% and 34%, which was associated with an increase in left ventricular function. Our data suggest that 31P MRS might be a valuable tool in the evaluation of apical ballooning, but larger cohorts are needed to improve the understanding of metabolic changes during transient apical ballooning.

Hybrid coronary artery revascularization: logistics and program development.

Planning hybrid coronary artery revascularization--a combination of cardiac surgery with percutaneous procedures--requires, at first sight, a very complex logistical setup. Technical and equipment related details should be defined as early as possible in order to have time for training of all OR personnel involved. The most challenging aspect in OR-located hybrid coronary revascularization remains a very close cooperation of cardiac surgeons and interventional cardiologists. This teamwork does include indication findings and subsequent referral of multivessel coronary artery disease patients to hybrid procedures, as well as high individual flexibility of interventionalists and surgeons. The major prerequisite for this cooperation is a mutual acceptance of different revascularization approaches and the intent to combine their most striking advantages. Intraoperative graft angiography during coronary artery bypass grafting (CABG) procedures is one important step toward simultaneous hybrid coronary revascularization procedures. We describe our experience with on table angiography using a mobile C-arm for intraoperative imaging. This fluoroscopy system can in selected cases be used for simultaneous hybrid procedures.

Vascular endothelial growth factor synthesis in vascular smooth muscle cells is enhanced by 7-ketocholesterol and lysophosphatidylcholine independently of their effect on nitric oxide generation.

Nitric oxide (NO) generated by inducible NO synthase (iNOS) enhances vascular endothelial growth factor (VEGF) synthesis in vascular smooth muscle cells (VSMC) and both NO and modified low density lipoprotein (LDL) augment VEGF production in macrophages. Oxidized LDL (oxLDL) are known inhibitors of NO generation in the cells of vascular wall. As the relationship between VEGF, iNOS and oxLDL has not been well elucidated, we studied the effect of two main components of oxLDL, 7-ketocholesterol (7-Kchol) and lysophosphatidylcholine (LPC), on VEGF and NO synthesis in rat VSMC and on VEGF synthesis in human VSMC. Both LPC and 7-Kchol significantly augmented VEGF production in rat and human VSMC. Increase in VEGF generation was related to the activation of VEGF promoter by both 7-Kchol and LPC and enhancement of VEGF mRNA transcription. In rat, VSMC IL-1beta-induced NO generation and enhanced VEGF synthesis. 7-Kchol decreased rat iNOS promoter activity, iNOS expression and NO generation, but it did not impair IL-1beta-induced VEGF synthesis. LPC did not significantly influence IL-1beta-induced NO production in rat VSMC and VEGF synthesis was significantly enhanced by combined treatment with IL-1beta and LPC in comparison to the effect of either compound alone. The results indicate that VEGF and NO synthesis in VSMC can be modulated by oxLDL. Those interactions might have an effect on the plaque growth and might be of relevance for the physiology of vascular wall cells.

Genetic augmentation of nitric oxide synthase increases the vascular generation of VEGF.

OBJECTIVE: Vascular endothelial growth factor (VEGF) induces the release of nitric oxide (NO) from endothelial cells. There is also limited data suggesting that NO may enhance VEGF generation. METHODS: To further investigate this interaction, we examined the effect of exogenous and endogenous NO on the synthesis of VEGF by rat and human vascular smooth muscle cells (VSMC) by exposing cells to exogenous NO donors, or to genetic augmentation of eNOS or iNOS. RESULTS: NO-donors potentiated by 2-fold the generation of VEGF protein by rat or human VSMC. Similarly, rat or human VSMC transiently transfected with plasmid DNA encoding eNOS or iNOS, synthesized up to 3-fold more VEGF than those transfected with control plasmid DNA, an effect which was reversed after treatment with the NOS antagonist L-NAME. Rat VSMC stably transfected with pKeNOS plasmid, constitutively produced NO and released high concentrations of VEGF. In these cells, L-NAME significantly reduced NO synthesis and decreased VEGF generation. The VEGF protein produced by NOS-transfected VSMC was biologically active, as conditioned media harvested from these cells increased endothelial cell proliferation. CONCLUSION: These studies reveal that NO derived from NO-donors or generated by NOS within the cells, upregulates the synthesis of VEGF in vascular smooth muscle cells. Administration of NO donors, or augmentation of endogenous NO synthesis, may be an alternative approach in therapeutic angiogenesis.

[Variability of coping strategies in coronary artery bypass surgery patients]. / Zur Variabilität des Coping bei Patienten mit aortokoronarer Bypass-Operation.

The state-versus-trait discussion in coping research would become more meaningful if attention is paid to the variability both of coping patterns in individual patients as well as stability of single coping strategies over time. 35 patients undergoing coronary artery bypass surgery were interviewed three times about their coping and stress experience: after cardiac catheterization, on the day before surgery, and six days after surgery. Anxiety and depression were measured. A coping attitude of "positive passivity" was present at all three points of time. While the group means were stable, vast interindividual differences occurred. Also, there was a high degree of scatter in the stability of single coping items; emotion related coping modes were more stable than cognition and action related ones. The variability of the patients' coping patterns correlated positively with the amount of stress experienced and with preoperative depression. Different coping strategies are linked to a different degree with personality traits, emotional coping modes revealing the closest connection. The variability of individual coping efforts might be linked to a personality disposition characterized by a vulnerability for stress and depressive reactions.

Head-to-head comparison of N-terminal pro-brain natriuretic peptide, brain natriuretic peptide and N-terminal pro-atrial natriuretic peptide in diagnosing left ventricular dysfunction.

Brain natriuretic peptide (BNP), NT-proBNP and NT-pro-atrial natriuretic peptide (NT-proANP) were measured in blood samples from 57 patients using immunoassays and immunoradiometric assays to evaluate the usefulness as diagnostic markers for the detection of heart failure. For the detection of impaired left ventricular ejection fraction (LVEF), receiver operating characteristic curves showed that BNP had the best diagnostic performance with an area under curve (AUC) of 0.75+/-0.06. However, NT-proBNP (AUC: 0.67+/-0.07) and NT-proANP (AUC: 0.69+/-0.08) showed no significant difference to BNP. In a further analysis for the detection of resting LVEF <40%, BNP again was the best marker with an AUC of 0.83+/-0.06. NT-proBNP showed only a slightly smaller AUC (0.79+/-0.07). The AUC for NT-proANP was significantly smaller (0.65+/-0.08) compared to BNP. Additionally, BNP and NT-proBNP correlated negatively with the resting LVEF (BNP: -0.472, p<0.001; NT-proBNP: -0.306, p=0.026), whereas NT-proANP showed no significant correlation. In summary, BNP was the best marker to detect patients with impaired LVEF compared to NT-proBNP and NT-proANP. However, NT-proBNP showed no significant differences to BNP and it is therefore a new promising alternative marker for the detection of left ventricular dysfunction.

Inappropriate detection of supraventricular arrhythmias by implantable dual chamber defibrillators: a comparison of four different algorithms.

Inappropriate therapy of supraventricular tachyarrhythmias by an ICD is still a common problem. Dual chamber (DDD) ICDs provide additional atrial sensing and should result in higher specificity for detection of supraventricular tachyarrhythmias. However, a direct comparison of different dual chamber algorithms has not been reported. The detection algorithms of four different DDD ICDs were tested: Phylax AV, Defender IV, Ventak AV III DR, and Gem DR 7271. Based on arrhythmias recorded from patients undergoing invasive electrophysiological studies and in many cases of catheter ablation at our institution, a library consisting of 71 supraventricular and 15 ventricular tachyarrhythmias was created. The library consists of episodes of atrial fibrillation, atrial flutter with different AV conduction, typical and atypical AV nodal reentrant tachycardia, AV reentrant tachycardia, sinus tachycardia, and ventricular tachycardia with and without ventriculoatrial conduction. Atrial fibrillation was appropriately classified by all four algorithms. However, the specificity for detection of other supraventricular tachyarrhythmias achieved by the Biotronik (12%) and the Guidant (11%) devices was significantly lower compared to the specificity of the ELA (28%) and the Medtronic DDD ICD (20%). This is due to the fact that the Biotronik and the Guidant algorithm classified all supraventricular tachyarrhythmias resulting in a stable ventricular rate as ventricular tachycardia, whereas the ELA and Medtronic algorithms performed a more detailed analysis by assessment of PR association, atrial onset, or timing of the atrial event relative to the ventricular event, respectively. Atrial fibrillation, the most common supraventricular tachyarrhythmia in patients with ICD, was detected by all devices.