István Czuriga

Cerebrovascular reactivity in hypertensive patients: A transcranial Doppler study

We studied the usefulness of transcranial Doppler sonography for assessing changes in vasoreactivity in patients with hypertension and the hemodynamic consequences of hypertension.

Comparison of the New Cardioselective Beta-Blocker Nebivolol with Bisoprolol in Hypertension: The Nebivolol, Bisoprolol Multicenter Study (NEBIS)

AbstractObjective: The aim of the present study was to evaluate the antihypertensive efficacy of the highly beta1-selective adrenergic antagonist nebivolol in comparison with bisoprolol in the treatment of mild to moderate essential hypertension. Methods: This multicenter, single-blind, randomized, parallel-group 16-week study involved a 4-week placebo run-in, followed by a 12-week treatment period (5 mg nebivolol or 5 mg bisoprolol). Patients (n = 273) eligible for the study had a sitting diastolic blood pressure (DBP) between 95 and 110 mm Hg and a systolic blood pressure (SBP) ≤180 mm Hg at the end of the placebo run-in period. The primary endpoint of the study was the percentage of responders achieving DBP normalization (≤90 mm Hg) or a DBP reduction of at least 10 mm Hg. Results: The baseline SBP and DBP were similar in the two groups. Both SBP and DBP decreased gradually and significantly upon treatment. The two treatments had similar effects on the mean change from the baseline for both DBP (nebivolol −15.7 ± 6.4 mm Hg vs. bisoprolol −16.0 ± 6.8 mm Hg) and SBP. A high proportion of responders was noted in both groups (nebivolol 92.0% vs. bisoprolol 89.6%) and there was no significant difference between the treatments. The overall number and incidence of spontaneously reported adverse events were slightly, but not significantly lower for nebivolol (8 events; 5.8%) than for bisoprolol (12 events; 8.9%). Conclusions: The findings of the present trial indicate that 5 mg nebivolol once daily is an effective antihypertensive agent. It can therefore be recommended as a useful alternative first-line treatment option for the management of patients with mild to moderate essential hypertension.

Metoprolol CR/XL in postmyocardial infarction patients with chronic heart failure: experiences from MERIT-HF.

BACKGROUND The benefit of beta-blockers post-myocardial infarction (MI) was established in the late 1970s. Major advances in the treatment of MI have since occurred. However, patients with chronic heart failure (CHF) were excluded from those trials. The purpose of this study was to assess the effect of beta-blockers in post-MI patients with CHF receiving contemporary management. METHODS This was a prespecified subgroup analysis of a double-blind, randomized trial: the Metoprolol CR/XL Randomized Intervention Trial in Heart Failure (MERIT-HF). Patients with CHF in New York Heart Association class II to IV with an ejection fraction (EF) < or =0.40 and a history of being hospitalized for an acute MI (n = 1926) were randomized to metoprolol succinate controlled release/extended release (CR/XL) versus placebo. Mean EF was 0.28, and the mean follow-up was 1 year. RESULTS Metoprolol CR/XL reduced total mortality by 40% (95% CI 0.20-0.55, P =.0004), and sudden death by 50% (95% CI 0.26-0.66, P =.0004). The combined end point of all-cause mortality/hospitalization for worsening CHF was reduced by 31% (95% CI 0.16-0.44, P <.0001), and cardiac death/nonfatal acute MI by 45% (95% CI 0.26-0.58, P <.0001). A post-hoc analysis showed that the outcome in patients with earlier revascularization (44%) and outcome in those with more severe CHF (20%) was similar to the entire post-MI population. CONCLUSIONS In post-MI patients with symptomatic CHF, beta-blockade continues to exert a profound reduction in mortality and morbidity in the presence of contemporary management that includes early and late revascularization, angiotensin-converting enzyme inhibitors, aspirin, and statins.

Interaction between homocysteine and lipoprotein(a) increases the prevalence of coronary artery disease/myocardial infarction in women: a case-control study.

INTRODUCTION Our aim was to investigate the association of elevated homocysteine (Hcy) and lipoprotein(a) Lp(a) with the prevalence of coronary artery disease (CAD) and myocardial infarction (MI) and to investigate their interaction in both genders. MATERIALS AND METHODS 955 (male/female: 578/377) consecutive patients admitted for coronary angiography were enrolled in the study. Lp(a), Hcy, vitamin B12, folic acid, MTHFR C677T polymorphism and traditional risk factors were determined. RESULTS 619 patients had significant (≥50%) stenosis (CAD+) and 341 had MI (MI+). CAD-MI- cases (n=302) were considered as controls. Adjusted Hcy levels were significantly elevated only in the female CAD+MI+group that was related to decreased vitamin B12 levels. Lp(a) was elevated in the CAD+MI+group of both genders. Folic acid levels and MTHFR T677 allele frequency did not show significant difference. Moderate hyperhomocysteinemia (Hcy >15μmol/L) or elevated Lp(a) (>300mg/L) increased the risk of CAD (OR 2.27, CI 1.36-3.80 and OR 1.64, CI 1.03-2.61, respectively) and MI (OR 2.52, CI 1.36-4.67 and OR 1.89, CI 1.06-3.38, respectively) only in women. Only simultaneous but not isolated elevation of Hcy and Lp(a) conferred a significant, 3.6-fold risk of CAD in females and even higher (11-fold) risk in young females, which suggested an interactive effect. CONCLUSIONS Moderate hyperhomocysteinemia or elevated Lp(a) level associated with a risk of CAD and MI only in women. While isolated elevation of one of the two parameters represented a mild risk of CAD, their combined elevation highly increased the risk in females. No such effect was observed in males.

Effects of autologous bone marrow derived CD34+ stem cells on the left ventricular function following myocardial infarction

Both experimental and human clinical studies executed in the last 5 years suggested that bone marrow derived cells may participate in the healing process after myocardial infarction. A number of small clinical trials indicated mild or moderate beneficial effect of intracoronary administration of bone marrow derived stem cells after myocardial infarction. Most of the studies used mononuclear cell fraction; due to the cellular heterogeneity of this cell population the type of the effective subpopulation was not known. We investigated the safety and functional effects of the autologous bone marrow CD34+ stem cells after intracoronary administration in patients with recent myocardial infarction. 8 patients with impaired left ventricular function were transplanted with CD34+ bone marrow stem cells 12 +/- 1 day after the acute coronary event. 2D-echocardiography, FDG-PET and MIBI-SPECT were performed before transplantation and 6 month later. During the 6-month follow-up the global left ventricular function (basal EF 37.3 +/- 2.9%, after cell therapy 44.8 +/- 4.1%) and regional viability / metabolism increased significantly (17.6 +/- 13.5%). The increase of myocardial perfusion in the infarct region was tendentious but not significant. Our results demonstrate for the first time that the CD34+ subpopulation of bone marrow derived stem cells improves left ventricular function and viability after myocardial infarction.

Transcranial Doppler Monitoring in Hypertensive Patients during Physical Exercise

Purpose: To evaluate the diagnostic value of a combined method, i.e. ergometer cycling with continuous bilateral transcranial Doppler monitoring (TCD) to detect cerebral hemodynamic abnormalities in recently diagnosed hypertensive patients. Methods: 30 neurologically symptom-free, nontreated patients with essential hypertension and 30 age- and sex-matched controls were studied. Carotid ultrasound, resting ECG and blood parameters were investigated. Cycling ergometry was performed according to the WHO protocol. Blood pressure, heart rate, end-tidal CO2 (etCO2) and bilateral middle cerebral artery (MCA) blood flow velocity (MV) were monitored. Results: At rest, MV in the MCA did not differ significantly between controls and hypertensive subjects. MV continuously increased in controls until the end of loading whereas a plateau was reached at 4 min in hypertensive subjects. During 6 min of cycling, the time course of absolute values of MV in the MCA and that of the changes in the ratio of mean velocity/end-tidal CO2 (ΔMV/ΔetCO2) differed significantly between hypertensive subjects and controls (p = 0.03 and p = 0.02, respectively). Conclusion: Ergometer cycling combined with TCD revealed altered vasoreactivity, therefore this may be a sensitive method for the detection of early hemodynamic impairment in nontreated hypertensive subjects.

Cellular mechanisms for diastolic dysfunction in the human heart.

Left ventricular (LV) diastolic dysfunction is an important contributor to many different cardiovascular diseases. LV diastolic dysfunction can manifest itself as slow LV relaxation, slow LV filling or high diastolic LV stiffness. Diastolic abnormalities have been described in the senescent heart, in heart failure with preserved ejection fraction (HFPEF), in diabetic cardiomyopathy, in aortic valve stenosis (AVS), in hypertrophic cardiomyopathy (HCM), as well as in Fabry disease (FD), however, exact cellular and molecular alterations behind the diastolic deterioration in these diseases are not yet completely characterized. Several studies thoroughly investigated altered cardiomyocyte function, changes of contractile myofilaments, extracellular collagen deposition and advanced glycation end products (AGEs) cross-linking in the background of diastolic dysfunction. These clinical and experimental data suggest that underlying mechanisms of LV diastolic dysfunction are divergent in different cardiac pathologies, therefore the present review aims to summarize mechanisms at the cellular level of diastolic abnormalities in various cardiovascular diseases.

Factor XIII B Subunit Polymorphisms and the Risk of Coronary Artery Disease

The aim of the case-control study was to explore the effect of coagulation factor XIII (FXIII) B subunit (FXIII-B) polymorphisms on the risk of coronary artery disease, and on FXIII levels. In the study, 687 patients admitted for coronary angiography to investigate suspected coronary artery disease and 994 individuals representing the Hungarian population were enrolled. The patients were classified according to the presence of significant coronary atherosclerosis (CAS) and history of myocardial infarction (MI). The F13B gene was genotyped for p.His95Arg and for intron K nt29756 C>G polymorphisms; the latter results in the replacement of 10 C-terminal amino acids by 25 novel amino acids. The p.His95Arg polymorphism did not influence the risk of CAS or MI. The FXIII-B intron K nt29756 G allele provided significant protection against CAS and MI in patients with a fibrinogen level in the upper tertile. However, this effect prevailed only in the presence of the FXIII-A Leu34 allele, and a synergism between the two polymorphisms was revealed. Carriers of the intron K nt29756 G allele had significantly lower FXIII levels, and FXIII levels in the lower tertile provided significant protection against MI. It is suggested that the protective effect of the combined polymorphisms is related to decreased FXIII levels.

Changes of cerebral hemodynamics in hypertensives during physical exercise.

BACKGROUND AND PURPOSE Previously, 30 untreated hypertensive patients were investigated by transcranial Doppler (TCD) monitoring during physical exercise, and changes of hemodynamic parameters were compared with those of age matched healthy subjects. After 3-year antihypertensive (AHT) treatment, these hypertensives were investigated again. The aim of this study was to compare the cerebral hemodynamic changes in the regularly treated and noncompliant (untreated) hypertensives during ergometer cycling. METHODS Nineteen of 30 previously untreated hypertensive patients could be investigated again using the same method as before. Eleven were regularly treated (treated hypertensive [T-HT] group), and 8 did not take their AHT medications due to lack of compliance (noncompliant hypertensive [NC-HT] group). Blood pressure, heart rate, end-tidal CO2 (etCO2; Capnogard capnograph), and bilateral middle cerebral artery mean blood flow velocity (MV) were continuously monitored during ergometer cycling according to the World Health Organization protocol. Values of 2-minute loading were analyzed. RESULTS Median loading time did not differ significantly between the T-HT and NC-HT groups. After 2 minutes of cycling in treated patients, the ratio of MV and etCO changes (DeltaMV/DeltaetCO2) showed similar values as before therapy (P = .38), whereas in noncompliant patients, a further worsening of the ratio of DeltaMV/DeltaetCO2 could be observed (P = .04). CONCLUSION The decrease of arteriolar vasodilation (ie, the ratio of DeltaMV/DeltaetCO2) could be demonstrated in the NC-HT group after 3 years. TCD combined with ergometer cycling is a useful method for evaluation of cerebral hemodynamic changes after AHT therapy.

Heart failure with preserved ejection fraction (diastolic heart failure)

Diastolic heart failure, which is also called as heart failure with preserved ejection fraction, is a clinical syndrome in which patients have signs and symptoms of heart failure, normal or near normal left ventricular ejection fraction (≥ 50%) and evidence of diastolic dysfunction. Recent epidemiological studies have demonstrated that more than half of all heart failure patients have diastolic heart failure. The syndrome is more common in women than in men and the prevalence increases with age. Patients with diastolic heart failure form a fairly heterogeneous group with complex pathophysiologic mechanisms. The disease is often in association with other comorbidities, such as hypertension, diabetes mellitus or obesity. The diagnosis of diastolic heart failure is best achieved by two-dimensional and Doppler echocardiography, which can detect abnormal myocardial relaxation, decreased compliance and increased filling pressure in the setting of normal left ventricular dimensions and preserved ejection fraction. Unlike heart failure with reduced ejection fraction, there is no such an evidence-based treatment for heart failure with preserved ejection fraction, which would improve clinical outcomes. Thus, pharmacological therapy of diastolic heart failure is based mainly on empiric data, and aims to the normalization of blood pressure, reduction of left ventricular dimensions and increased heart rate, maintenance of normal atrial contraction and treatment of symptoms caused by congestion. Beneficial effects of angiotensin-converting enzyme inhibitors and angiotensin-receptor blockers may be utilized in patients with diastolic dysfunction, especially in those with hypertension. Beta-blockers appear to be useful in lowering heart rate and thereby prolonging left ventricular diastolic filling time, while diuretic therapy is the mainstay of treatment for preventing pulmonary congestion. Nonetheless, treatment of the underlying disease is also an important therapeutic approach. This review summarizes the state of current knowledge with regard to diastolic heart failure.