Biomedical subjects

Dariusz Wojciechowski

Publications and source records attributed to Dariusz Wojciechowski.

4 recordsLinked to original sources

PubMed2005

Angiotensin II AT1 receptor density on blood platelets predicts early left ventricular remodelling in non-reperfused acute myocardial infarction in humans.

BACKGROUND: Renin-angiotensin-system activity, a principal factor determining ventricular remodelling after myocardial infarction (MI), is dependent on local angiotensin II concentration and angiotensin AT1 receptor (AT1R) density. The latter is regulated by systemic factors acting independently from angiotensin II concentration. OBJECTIVE: To test the hypothesis that AT1R density at the onset of MI determines post-MI ventricular remodelling. METHODS: In 48 patients with first acute MI who did not undergo reperfusion therapy, angiotensin AT1R density on blood platelets (reflecting cardiovascular AT1R density) was assessed 13+/-5 h after the onset of MI, using radioligand binding assay. Left ventricular end-systolic (LVESVI) and end-diastolic volume indices (LVEDVI) and ejection fraction (EF) were assessed by two-dimensional echocardiography as measures of ventricular remodelling. RESULTS: Predischarge LVESVI and LVEDVI positively and EF negatively correlated with AT1R density. Patients with AT1R density below median had significantly lower LVESVI (33.2+/-2.4 mL/m2), LVEDVI (70.0+/-2.8 mL/m2) and higher EF (52.8+/-2.3%) than patients with AT1R density above median (LVESVI = 44.9+/-2.6, LVEDVI = 81.3+/-3.9 mL/m2 and EF = 44.9+/-2.6%, all p<0.01). In multivariate analysis, only AT1R density and infarct size were independent predictors of early post-MI ventricular dilation. CONCLUSIONS: High density of AT1R at the onset of MI is a predictor of early left ventricular remodelling.

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PubMed2005

Effect of angiotensin-converting enzyme or vasopeptidase inhibition on ventricular size and function in patients with heart failure: the Omapatrilat Versus Enalapril Randomized Trial of Utility in Reducing Events (OVERTURE) echocardiographic study.

BACKGROUND: Angiotensin-converting enzyme (ACE) inhibition attenuates ventricular remodeling and improves ventricular function in heart failure patients. Vasopeptidase inhibition has shown similar effects in experimental models. OBJECTIVES: The OVERTURE echocardiographic study was designed to test the hypothesis that the vasopeptidase inhibitor omapatrilat would attenuate ventricular remodeling and improve ventricular function to a greater extent than an ACE inhibitor. METHODS: Three hundred twenty-one patients with heart failure (New York Heart Association class > or = 2) were included in the OVERTURE echocardiographic substudy and were randomized to receive enalapril (10 mg twice a day) or omapatrilat (40 mg every day). Echocardiograms were performed at baseline and at 1 year (n = 214). Left ventricular size was estimated by summation of ventricular areas in apical and short-axis views and by calculation of ventricular volumes. Ejection fraction was calculated from ventricular volumes. RESULTS: Combined diastolic and systolic areas and volumes decreased significantly (mean diastolic area change -8.36 cm2, 95% CI -9.4 to -7.3 cm2; mean systolic change -8.4 cm2, 95% CI -9.5 to -7.3 cm2), and ejection fractions increased significantly (3.6%, 95% CI 2.6% to 4.6%) in both treatment groups from baseline to 1 year. There were no differences in the magnitude of improvement in ventricular size or function based on treatment assignment. Patients who died or were hospitalized for heart failure subsequent to the final assessment demonstrated the least degree of reverse remodeling. CONCLUSION: Ventricular size and function improved similarly after 1 year with ACE or vasopeptidase inhibition in patients with heart failure. Reverse remodeling was associated with improved outcome.

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PubMed2003

Clinical performance of automatic closed-loop stimulation systems.

Inos pacemakers use contraction dynamics to regulate the pacing rate according to the Closed-Loop Stimulation (CLS) principle. The physician can program only the lower and upper rate limits, while the internal rate responsive parameters are continually adjusted to changing patient conditions. Seventy-two patients with sinus node disease were enrolled in the multicenter Rate Behavior of the Pacing System Inos (2) CLS during Daily Life (RAPID) study to evaluate the appropriateness of CLS rates during daily activities and the long-term stability of the system. The pacemakers clearly differentiated between climbing stairs, descending stairs, and slow walking, with the corresponding peak rates of 104 +/- 18, 95 +/- 15, and 88 +/- 11 beats/min, respectively (P < 0.001 for any pair of activities). The peak CLS rate during the color-word test was significantly higher than that at rest (80 +/- 8 vs 67 +/- 7 beats/min, P = 0.002). The 24-hour heart rate trends retrieved from the pacemaker memory at 3, 6, and 12 months after implantation appeared appropriate in all patients except for two whose pacing rates were occasionally too fast during the night. Mean diurnal and nocturnal rates determined at 3-month, 6-month, and 12-month examinations fluctuated only slightly, from 74.6-75.3 beats/min (diurnal,P = NS) and from 67.0-68.1 beats/min (nocturnal,P = NS), indicating a satisfactory long-term stability of the system. The incidence of atrial pacing events during the entire follow-up was 82 +/- 18%. A 6.5-8.3 beats/min difference, on average, between day and night (P < 0.001)and distinction between different daily activities seem to evidence sensitivity of the automatic CLS-driven pacemakers to physiological demands despite minimum programming requirements.

Activities of Daily Living↗

PubMed2002

Calcium blocker therapy before myocardial infarction increases post-infarction short- and long-term mortality. Data from the INJECT trial.

BACKGROUND: Short-acting calcium channel blockers (Ca-blockers) have been shown in some studies to increase the risk of myocardial infarction (MI) and post-MI complications. Data from large, international, randomised studies such as the INJECT trial may bring new important information on the effects of medication used before MI, on the course of MI and post-MI complications. AIM: To assess the effects of beta-blocker and Ca-blocker therapy administered prior to MI on the early and late outcome after MI. METHODS: The study group consisted of 6001 patients with acute MI treated according to the INJECT protocol. The patients were divided into four groups according to the type of treatment before the index MI: Group I (n=580) - patients treated with beta-blockers; Group II (n=831) - patients treated with Ca-blockers; Group III (n=277) - patients treated with both beta-blockers and Ca-blockers; and Group IV (n=4313) - no beta-blocker or Ca-blocker treatment. The analysed end-points were 35- and 180-day mortality as well as angina recurrences, occurrence of heart failure, atrial fibrillation/flutter and asystole. RESULTS: During hospital stay, supraventricular arrhythmias, asystole, recurrent ischaemia and heart failure occurred more frequently in patients from groups II and III than in other groups. Early mortality was significantly higher in group II (p<0.001) and group III (p<0.002) than in group IV. Late mortality was the lowest in group IV, followed by group I. Cox proportional hazards multivariable analysis revealed that hypotension, Killip class IV (p<0.001), previous Ca-blocker (p<0.01) or Ca- and beta-blocker treatment (p<0.01) as well as previous MI (p<0.05) were the independent predictors of death. CONCLUSIONS: Compared with beta-blocker therapy or no treatment, previous use of Ca-blockers increases both early and long-term complication rates in patients with MI.

Journal Article↗