Improved in-hospital outcome for radial access in a large contemporary cohort of primary percutaneous coronary intervention.

BACKGROUND: Randomised controlled trials have shown diverse results for radial access in patients undergoing primary percutaneous coronary intervention (PPCI). Moreover, it is questionable whether radial access improves outcome in patients with cardiogenic shock undergoing PPCI. We aimed to investigate the outcome according to access site in patients with or without cardiogenic shock, in daily clinical practice. METHODS: For the present analysis we included 9,980 patients undergoing PPCI between 2012 and 2018, registered in the multi-centre, nationwide registry on PCI for myocardial infarction (MI). In-hospital mortality, major adverse cardiovascular events (MACE), and net adverse clinical events (NACE) until discharge were compared between 4,498 patients with radial (45%) and 5,482 patients with femoral (55%) access. RESULTS: Radial compared to femoral access was associated with lower in-hospital mortality (3.5% vs. 7.7%; P<0.01). Multivariable logistic regression analysis confirmed reduced in-hospital mortality [odds ratio (OR) 0.57, 95% confidence interval (CI): 0.43 to 0.75]. Furthermore, MACE (OR 0.60, 95% CI: 0.47 to 0.78) as well as NACE (OR 0.59, 95% CI: 0.46 to 0.75) occurred less frequently in patients with radial access. Interaction analysis with cardiogenic shock showed an effect modification, resulting in lower mortality in PCI via radial access in patients without, but no difference in those with cardiogenic shock (OR 1.78, 95% CI: 1.07 to 2.96). CONCLUSIONS: Radial access for patients with acute MI undergoing PPCI is associated with improved survival in a large contemporary cohort of daily practice. However, this beneficial effect is restricted to hemodynamically stable patients.

Predictors of transportation delay in patients with suspected ST-elevation-myocardial infarction in the VIENNA-STEMI network.

OBJECTIVE: The emergency medical service (EMS) provides rapid pre-hospital diagnosis and transportation in ST-elevation myocardial infarction (STEMI) systems of care. Aim of the study was to assess temporal and regional characteristics of EMS-related delays in a metropolitan STEMI network. METHODS: Patient call-to-arrival of EMS at site (call-to-site), transportation time from site to hospital (site-to-door), call-to-door, patient's location, month, weekday, and hour of EMS activation were recorded in 4751 patients referred to a tertiary center with suspicion of STEMI. RESULTS: Median call-to-site, site-to-door, and call-to-door times were 9 (7-12), 39 (31-48), and 49 (41-59) minutes, respectively. The shortest transportation times were noted between 08:00 and 16:00 and in general on Sundays. They were significantly prolonged between midnight and 04:00, whereby the longest difference did not exceed 4 min in median. Patient's site of call had a major impact on transportation times, which were shorter in Central and Western districts as compared to Southern and Eastern districts of Vienna (p < 0.001 between-group difference for call-to-site, site-to-door, and call-to-door). After multivariable adjustment, patient's site of call was an independent predictor of call-to-site delay (p < 0.001). Moreover, age and hour of EMS activation were the strongest predictors of call-to-site, site-to-door, and call-to-door delays (p < 0.05). CONCLUSION: In our Viennese STEMI network, the strongest determinants of pre-hospital EMS-related transportation delays were patient's site of call, patient's age, and hour of EMS activation. Due to the significant but small median time delays, which are within the guideline-recommended time intervals, no impact on clinical outcome can be expected.

Impact of age on short- and long-term mortality of patients with ST-elevation myocardial infarction in the VIENNA STEMI network.

BACKGROUND AND AIM: Our senescent society includes a growing number of elderly people suffering from ST-elevation myocardial infarction (STEMI); however, exactly this population is often underrepresented in randomized trials. Hence, our aim was to investigate the influence of age on patient characteristics, as well as short- and long-term outcome in the Vienna STEMI registry. METHODS: We included all patients of the Vienna STEMI registry (2003-2009). Patients were stratified into age cohorts (≤45, 46-59, 60-79 and ≥80 years, respectively). Differences between cohorts were investigated by descriptive statistics and regression models. Crude and adjusted mortality rates were investigated using log rank test and Cox regression models, respectively. The influence of treatment on mortality was further investigated using propensity score matching. RESULTS: A total of 4579 patients fulfilled the criteria for further investigation. With rising age of cohorts, the number of females, diabetes mellitus (DM), hypertension (HTN), previous myocardial infarction (MI), shock, no reperfusion therapy and anterior wall infarction significantly increased. In contrast, the number of patients with a positive family history, smoking and hyperlipidemia (HLP) significantly declined. Log rank analysis showed significant differences between age cohorts for short- and long-term mortality. Cox regression analysis for short-term mortality revealed an independent association for age at the event, HTN and shock, while age, smoking, DM, HTN, HLP, previous MI and shock independently influenced long-term mortality after correction for confounders. Also, we found a significant association of age and total ischemic time (TIT), which however had no influence on long-term mortality (interaction term p = 0.236). Propensity score matching revealed reduced mortality rates for patients who received reperfusion therapy compared to conservative management, irrespective of age. CONCLUSIONS: Increasing age independently influenced short- and long-term mortality in patients with STEMI in the Vienna STEMI network. The TIT significantly increased with baseline age, but had no impact on mortality. Furthermore, reperfusion therapy exerted beneficial effects irrespective of the patients' age.

Impact of time of admission on short- and long-term mortality in the Vienna STEMI registry.

BACKGROUND: Several studies have shown contradictive findings regarding mortality and hospital admission time in patients presenting with ST-elevation myocardial infarction (STEMI). The aim of this study was to assess the impact of "on-" or "off-hour" admission on short- and long-term all-cause mortality of patients in the advanced Vienna STEMI network between 2003 and 2009. METHODS AND RESULTS: In total, 2829 patients were included into this analysis. Patients were stratified according to admission time into "on-hour" admission (07:30 until 15:00h on weekdays) and "off-hour" admission (15:00-7:30h on weekdays and 24h on weekends). As endpoint of interest, all-cause mortality was investigated after 30days and 3years of follow-up, the latter for all patients and as Landmark analysis for survivors of the index event. Mean age was 60.5±13.3years, 2048 (72.4%) patients were male and 1260 (44.5%) patients presented with anterior wall infarction. 683 (24.1%) patients were admitted "on-hours", 2146 (75.9%) patients were admitted "off-hours". All-cause death occurred in 176 (6.2%) patients after a follow-up of 30days and in 337 (11.9%) patients after 3years. For short- and long-term all-cause mortality no significant differences could be detected between "on-" and "off-hour" admission in univariate and multivariate Cox proportional hazard analyses as well as for propensity score adjusted outcome analysis. CONCLUSION: In the Vienna STEMI network, "on-" or "off-hour" admission had no impact on short- and long-term mortality for all-comers presenting with acute STEMI. Our findings confirm the imperative need for well-structured STEMI networks of care, as previous data repeatedly demonstrated increased adverse cardiovascular outcome for "off-hour" admission.

Gender differences in short- and long-term mortality in the Vienna STEMI registry.

BACKGROUND: Data obtained from registries have shown that women diagnosed with STEMI are older, have more co-morbidities and a worse clinical outcome than men. Aim of this study was to investigate potential gender differences in in-hospital and long-term mortality in patients from Vienna STEMI registry (2003-2009). PATIENTS AND METHODS: Data from 4593 patients who were enrolled from January 2003 until December 2009 into the Vienna STEMI registry were analyzed. Gender-related differences in patient characteristics, time delays, reperfusion therapy, as well as short- and long-term all-cause mortality were investigated. A landmark analysis was performed to assess long-term all-cause mortality in patients after discharge. Multivariate regression analysis was performed in order to correct for confounders. RESULTS: Mean age, history of hypertension, diabetes mellitus and shock at presentation were significantly higher in women compared to men, whereas men were more frequently smokers, had more frequently a positive family history, a history of previous myocardial infarction and received more often GbIIb/IIIa inhibitors and reperfusion therapy. Overall the only significant difference in time delays was found in the onset of pain-to first medical contact time, which was significantly prolonged in women. Unadjusted in-hospital mortality, long-term mortality and long-term mortality for in-hospital survivors were statistically higher for women. After adjustment for confounders, multivariate analysis revealed no differences in mortalities between males and females. CONCLUSION: The higher risk profile and the prolonged delay between onset of pain-to-first medical contact are responsible for the higher unadjusted mortality rates in women. Difference in short and long-term mortalities is no more existent after statistical correction for confounders such as age, co-morbidities and significantly different time delay.

Clinical predictors of patient related delay in the VIENNA ST-elevation myocardial infarction network and impact on long-term mortality.

BACKGROUND: While contributors to system delay in ST-elevation myocardial infarction (STEMI) are well described, predictors of patient-related delays are less clear. The aim of this study was to identify predictors that cause delayed diagnosis of STEMI in a metropolitan system of care (VIENNA STEMI network) and to investigate a possible association with long-term mortality. METHODS: The study population investigated consisted of 2366 patients treated for acute STEMI in the Vienna STEMI registry from 2003-2009. Multivariable regression modelling was performed for (a) onset of pain to first medical contact (FMC) as a categorical variable (pain-to-FMC⩽60 min versus >60 min: 'early presenters' versus 'late presenters'); and for (b) onset of pain-to-FMC (min) as a continuous variable. RESULTS: After multivariable adjustment, female sex (odds ratio (OR) 1.348; 95% confidence interval (CI) 1.013-1.792; p=0.04) and diabetes mellitus (OR 1.355; 95% CI 1.001-1.835; p=0.05) were independently associated with late presentation in STEMI patients, whereas cardiogenic shock (OR 0.582; 95% CI 0.368-0.921; p=0.021) was a predictor of early diagnosis. When onset of pain-to-FMC was treated as a continuous variable, female sex ( p=0.003), anterior infarction ( p=0.004) and diabetes mellitus ( p=0.035) were independently associated with longer delay, while hyperlipidaemia ( p=0.002) and cardiogenic shock ( p=0.017) were strong predictors of short pain-to-FMC times. Three-year-all cause mortality was 9.6% and 11.3% ( p=0.289) for early and late presenters, respectively. After adjustment for clinical factors (sex, age, diabetes, current smoking, hypertension, hyperlipidaemia, cardiogenic shock and location of myocardial infarction) only a trend for increased risk of all-cause death was observed for longer pain-to-FMC times in a cox regression model (hazard ratio (HR) 1.012; 95% CI 0.999-1.025 for every 10 min of delay; p=0.061). Interestingly, early presentation within one hour of symptom onset was not associated with three-year mortality survival (HR 1.031; 95% CI 0.676-1.573; p=0.886). CONCLUSION: In this all-comers study of STEMI patients in the VIENNA STEMI network, cardiogenic shock was the strongest predictor of short patient-related delays, whereas a history of diabetes and female sex were independent associated with late diagnosis in STEMI. After adjustment for clinical confounders, patient related delay did not significantly impact on long-term all-cause mortality.

One-year mortality in patients with acute ST-elevation myocardial infarction in the Vienna STEMI registry.

BACKGROUND AND AIM: Systems of care to treat acute ST-elevation myocardial infarction (STEMI) have been developed world wide in the past decade. Their effectiveness can only be proven by including and analyzing outcome data of consecutive patients in registries, which is not the case in the majority of STEMI networks. This study investigates 1-year mortality in STEMI patients in Vienna included over a 14 months time interval. The Vienna STEMI network is organized by a specific rotational system and offers both, primary percutaneous intervention (PPCI) and thrombolytic therapy (TT) as reperfusion strategies according to the recent guidelines. METHODS: At the time of investigation, the Vienna STEMI network consisted of the Viennese Ambulance Systems and five high-volume interventional cardiology departments. This network has been organized in order to increase the number of STEMI patients admitted for PPCI and to offer the fastest available reperfusion strategy, in the majority PPCI but in selected patients also TT (STEMI of short duration, mainly anterior wall MI and mainly patients younger than 75 years), followed by rescue PCI in non-responders and elective angiography with/without PCI in responders to TT during the index hospital stay. RESULTS: One-year all-cause mortality rates in the Vienna STEMI network by use of the fastest available reperfusion strategy were 13.4% in patients who received reperfusion therapy after 2 h of symptom onset and 7.4% in patients treated within 2 h; (p = 0.017). Whereas PPCI and TT demonstrated a nonsignificant difference in 1-year mortality rates when initiated within 2 h of symptom onset (10.0% vs 5.7%; p = 0.59), PPCI was more effective in acute STEMI of > 2 h duration as compared to TT but this difference did not reach statistical significance (12.1% vs 18.2%; p = 0.07). CONCLUSIONS: The reassuring long-term results of the Viennese STEMI network are another example of a specific regional system of care to offer timely diagnosis, transfer and reperfusion in patients with STEMI. In contrast to other metropolitan areas where TT has almost completely abandoned, we still use pharmacological reperfusion as a backup in case of expected and unacceptable time delays for PPCI in order to reduce myocardial damage especially in patients with larger infarctions of short duration with a low risk of bleeding complications.

Efficacy and tolerability of olmesartan medoxomil in patients with mild to moderate essential hypertension: the OLMEBEST Study.

BACKGROUND AND OBJECTIVE: Achieving target BP is important to control the increased cardiovascular risk associated with uncontrolled hypertension. However, failure to respond to therapy is common with all classes of antihypertensive agents. Angiotensin II type 1 receptor antagonists (angiotensin receptor blockers [ARBs]) possess many of the positive features of angiotensin-converting enzyme inhibitors, with fewer adverse effects. However, many patients fail to respond adequately to low-dose monotherapy. This study examined whether olmesartan medoxomil dose titration and olmesartan medoxomil/hydrochlorothiazide combination therapy were therapeutically equivalent in patients with mild to moderate essential hypertension who had shown an inadequate response to low-dose olmesartan medoxomil monotherapy. METHODS: This was a prospective, parallel group, partially randomised, double-blind study set in 463 centres in nine European countries. 2306 male and female adult patients aged 18-75 years with mild to moderate essential hypertension (sitting diastolic BP [DBP] > or =90mm Hg and <110mm Hg) were enrolled. All enrolled patients received open-label olmesartan medoxomil 20mg once daily for 8 weeks. At the end of this period, patients whose BP had not normalised (sitting DBP > or =90mm Hg) were randomised to receive olmesartan medoxomil monotherapy (40mg once daily, n = 302) or olmesartan medoxomil (20mg once daily)/hydrochlorothiazide (12.5mg once daily) combination therapy (n = 325) for 4 weeks. The main outcome measure was change in mean sitting DBP during randomised treatment. RESULTS: After 8 weeks of open-label treatment with olmesartan medoxomil 20 mg/day, 76% of patients showed a DBP response (sitting DBP <90mm Hg or reduction of > or =10mm Hg). During the randomised phase of the study, both treatments were associated with further improvements in sitting SBP/DBP: a reduction of 5.3/5.1mm Hg with olmesartan medoxomil 40 mg/day, and a reduction of 10.8/7.9mm Hg with olmesartan medoxomil/hydrochlorothiazide combination therapy. Final mean BPs of 145.3/90.9mm Hg (olmesartan medoxomil 40 mg/day) and 140.7/88.7mm Hg (olmesartan medoxomil 20mg + hydrochlorothiazide) were achieved, compared with a mean BP of 160.8/100.5mm Hg at baseline. The two treatments were not therapeutically equivalent. Sitting DBP showed a response and was normalised (<90mm Hg) in 62% and 47% of olmesartan medoxomil monotherapy patients, respectively. In the combination therapy group, these endpoints were achieved by 71% (response) and 59% (normalisation) of patients. Treatment with olmesartan medoxomil 40 mg/day was associated with a lower frequency of adverse events than olmesartan medoxomil/hydrochlorothiazide combination therapy (21.5% vs 28.3%, respectively). CONCLUSION: For patients who did not achieve adequate BP control after initial treatment with olmesartan medoxomil 20 mg/day, olmesartan medoxomil dose titration (to 40 mg/day) or addition of hydrochlorothiazide (12.5 mg/day) elicited a sitting DBP response in the majority of patients who had failed to respond to low-dose monotherapy, and normalisation of sitting DBP in approximately 50% of patients. Both these strategies represent effective and well tolerated treatment options in patients who show an inadequate response to low-dose monotherapy with olmesartan medoxomil.

Effect of radio contrast media on residual renal function in peritoneal dialysis patients--a prospective study.

BACKGROUND: Residual renal function is an independent predictor of survival in peritoneal dialysis patients. Systemic administration of radio contrast media (CM) may increase the risk of acute renal failure in patients with impaired renal function not on dialysis. There are few data on the influence of CM administration in dialysis patients. METHODS: We investigated residual renal function in 10 continuous ambulatory peritoneal dialysis (CAPD) patients who underwent elective diagnostic intravenous or intra-arterial administration of CM (study group). Iopromide (a iodinated, non-ionic hypo-osmolar CM) was used for all interventions. The median dose of CM given was 107.5 ml/patient. Residual renal function (calculated as the average of renal creatinine and renal urea clearance) was measured on the day before the intervention (baseline), on days 1-7, day 10 and day 30 after intervention. Eight CAPD patients without exposure to CM acted as the control group. RESULTS: There was no significant difference between the two groups in age, gender, diabetes, duration of dialysis and renal clearance at baseline. In the study group, we observed a temporary decline of residual renal clearance after administration of CM (P<0.05; Friedman test). On day 30, clearances were not significantly different from baseline. In the control group, there was no significant change of residual clearance during the observation period. Repeated measures ANOVA revealed no significant difference in the course of residual renal function between study and control groups. The decline of residual renal clearance between baseline and a routine visit after 4 months was comparable between groups. CONCLUSION: Administration of iopromide did not lead to a persistent decline of residual renal function in CAPD patients. Nevertheless, non-ionic hypo-osmolar CM should be given to these patients with the lowest possible dose and only if there is a real clinical indication.

Atorvastatin reduces thrombin generation after percutaneous coronary intervention independent of soluble tissue factor.

INTRODUCTION: Statins were previously shown to suppress cellular tissue factor (TF) in vitro. Here, we investigated the effect of atorvastatin on the TF-pathway and thrombin generation after coronary angioplasty and stenting in vivo. MATERIALS AND METHODS: A cohort of 30 patients with coronary artery disease (CAD) was randomised to treatment with either none (n=10), 10 mg (n=10) or 80 mg (n=10) atorvastatin per day for the postinterventional period of 6 months starting the day before percutaneous coronary intervention (PCI). Fasting blood samples were collected on admission and after 6 weeks and 6 months of statin therapy to determine sTF, free tissue factor pathway inhibitor (TFPI) and prothrombin fragment F1.2 by immunoassay. RESULTS: Soluble TF (sTF) significantly correlated with thrombin generation as measured by prothrombin fragment F1.2 at baseline. This correlation was lost 6 weeks and 6 months after initiation of statin therapy. In vivo, F1.2 was significantly lowered after 6 months of statin therapy by both, low dose (0 vs. 10 mg: 1.3+/-0.3 vs. 0.7+/-0.2 ng/ml; P<0.05) and high dose (0 vs. 80 mg: 1.2+/-0.3 vs. 0.6+/-0.2 ng/ml; P=0.01) atorvastatin compared to control. However, sTF and free TFPI did not change significantly with atorvastatin therapy when compared to baseline or control. CONCLUSIONS: Our results demonstrate reduced in vivo generation of thrombin six months after percutaneous coronary intervention and statin therapy independent of sTF and free TFPI.

Predictors of early reangiography within 30 days after coronary stenting.

BACKGROUND: A substantial number of early urgent reangiographies after coronary stenting do not reveal coronary abnormalities such as thrombosis, dissection, restenosis or side branch occlusion. The characterization of patients undergoing early reangiography may reduce the number of potentially unnecessary procedures. OBJECTIVE: To evaluate the predictors for unplanned early re- angiography on the basis of the information available at the time of stent implantation. METHODS: All 71 patients with reangiography after stent implantation between 1994 and 1998 in the Department of Cardiology at the University Hospital of Vienna, Austria, were compared with a control sample of 88 patients without early reangiography during the same period (control subjects were matched for the time point of the first intervention). The clinical and procedural variables were analyzed in this case-control study. For specification of the group with negative reangiograms, differences in clinical parameters between patients with negative versus patients with positive reangiograms were also analyzed. RESULTS: Clinical predictors for early reangiography of patients without evidence of important coronary pathology were a history of hypertension and left ventricular hypertrophy, as well as total cholesterol. The angiographic predictor was multiple vessel disease, and procedural risk factors included the left anterior descending artery as the target artery, type B and C lesions and total occlusion in the left anterior descending artery, as well as high-pressure balloon stent deployment. CONCLUSION: Clinical, angiographic and procedural variables predict the risk for unplanned early reangiography after coronary stenting. Hypertensive heart disease may mimic acute coronary events; hypertension and left ventricular hypertrophy represent independent predictors of unplanned reangiography in patients with good short-term results.

Intracoronary thrombectomy with the X-sizer catheter system improves epicardial flow and accelerates ST-segment resolution in patients with acute coronary syndrome: a prospective, randomized, controlled study.

BACKGROUND: In patients with acute coronary syndrome (ACS), percutaneous coronary intervention (PCI) may cause thrombus dislodgment followed by reduced flow and impaired microcirculatory function. We prospectively compared conventional PCI to a strategy of additional pretreatment using the X-sizer thrombectomy system. METHODS AND RESULTS: Sixty-six patients (51 [77%] men; 54.9+/-9.9 years) with ACS (49 with ST-elevation infarction [STEMI]) and suspected intracoronary thrombus were randomized 1:1 to pretreatment with X-sizer and conventional PCI alone. Various aspects of epicardial flow and microvascular function were studied. Baseline data were similar in both groups. Postprocedural TIMI 3 flow was obtained in 90% of X-sizer-treated patients and in 84% of controls (NS); however, corrected TIMI frame count was lower in X-sizer- treated patients (18.3+/-10.2 versus 24.7+/-14.1; P<0.05). No significant group differences were observed in final coronary flow reserve, myocardial blush grade, and myocardial dye intensity. In STEMI, the sum of ST elevation was significantly lower in X-sizer-treated patients immediately after (2.78+/-3.05 versus 6.15+/-6.32 mm; P<0.03) and 6 hours after (2.17+/-2.31 versus 4.14+/-3.7 mm; P<0.05) intervention. ST-segment resolution >50% was observed in 83% of X-sizer-treated patients and in 52% of controls (P<0.03). Multivariate analysis identified X-sizer treatment as the single independent predictor of ST-segment resolution >50% (OR 4.35; 95% CI, 1.13 to 16.9; P<0.04). Major adverse cardiac events after 30 days occurred in 2 patients in each group. CONCLUSIONS: In ACS with suspected thrombus, pretreatment with the X-sizer catheter system improves epicardial flow and accelerates ST-segment resolution compared with conventional PCI alone.

Prognostic impact of workload in patients with congestive heart failure.

AIMS: Recent data underline the prognostic value of cardiopulmonary exercise parameters (eg, peak oxygen consumption [PVO2]), percentage of predicted oxygen consumption [ppVO2], ventilation, and workload) in patients with congestive heart failure. These parameters were not yet compared in a multivariate analysis. METHODS AND RESULTS: To detect the superiority of one of these parameters, in a prospective 1-year follow-up study we investigated 226 patients with heart failure. The end point of the study was combined death and prioritization for urgent cardiac transplantation within 1 year. Cardiopulmonary exercise testing was performed with evaluation of peak oxygen consumption, percentage of predicted peak oxygen consumption, peak carbon dioxide production, ventilation, workload, anaerobic threshold, and ventilation/carbon dioxide production ratio. All variables were univariate predictors of 1-year mortality and urgent transplantation. Multivariate analysis demonstrated that only workload and ventilation were independently related to 1-year mortality and urgent cardiac transplantation, whereas peak oxygen consumption or percentage of predicted peak oxygen consumption did not reach statistical significance in this model. CONCLUSION: Workload on bicycle stress test correlates to 1-year mortality. More important, workload is a more powerful predictor of 1-year survival compared with established markers such as pVO2 or ppVO2.

Contribution of nicotine to acute endothelial dysfunction in long-term smokers.

OBJECTIVES: The aim of this study was to determine whether nicotine, a constituent of cigarette smoke, contributes to acute endothelial dysfunction after smoking one cigarette. BACKGROUND: Animal studies suggest that nicotine might cause an impairment of endothelium-dependent vasodilation via an increase in oxidative stress. METHODS: Sixteen healthy smokers were entered into a randomized, observer-blinded crossover study comparing the effects of nicotine nasal spray (1-mg nicotine) and cigarette smoke (1-mg nicotine, 12 mg tar) on vascular reactivity in the brachial artery. Using high-resolution ultrasound, flow-mediated dilation (FMD) and endothelium-independent, nitroglycerin-induced dilation were assessed at baseline and 20 min after the administration of nicotine (spray or cigarette). RESULTS: In response to similar increases in nicotine serum levels, FMD values declined from 10.2 +/- 4.4% to 6.7 +/- 4.0% after the spray (mean difference: -3.6 +/- 2.0%, 95% confidence interval: -4.6; -2.5, p < 0.0001) and from 9.4 +/- 3.8% to 4.3 +/- 2.8% after the cigarette (-5.1 +/- 2.6%, -6.5; -3.7, p < 0.0001). Nitroglycerin-induced dilation remained similar within both periods. Performing a period effect analysis of variance, a significant influence on FMD was found for the mode of administration (p = 0.017) and the baseline value (p = 0.021). The effect on FMD was more pronounced after the cigarette than after the spray (estimated average effect difference: 1.9% FMD). Oxidation parameters did not increase significantly after nicotine spray or tobacco exposure. CONCLUSIONS: These results demonstrate that nicotine alone causes acute endothelial dysfunction, although to a lesser extent than smoking a cigarette of the same nicotine yield. However, the precise mechanisms by which nicotine leads to this altered vascular reactivity remain unclear.