Biomedical subjects

Erich Kvas

Publications and source records attributed to Erich Kvas.

3 recordsLinked to original sources

PubMed2005

Increased arterial wave reflections predict severe cardiovascular events in patients undergoing percutaneous coronary interventions.

AIMS: Increased arterial wave reflections are associated with the presence and extent of coronary atherosclerosis and with cardiovascular mortality in selected populations. We prospectively evaluated their prognostic value in the short- and long-term following percutaneous coronary interventions (PCIs). METHODS AND RESULTS: We non-invasively quantified wave reflections [expressed as augmentation index corrected for heart rate of 75 b.p.m. (AIx@75)] using applanation tonometry of the radial artery and a validated transfer function to obtain the corresponding aortic values in 262 patients undergoing PCI. During 2-year follow-up, 61 patients reached the primary endpoint [death, myocardial infarction (MI), and restenosis]. Increasing tertiles of Alx@75 were related to the rate of patients reaching the primary endpoint [15.2, 20 and 35.3%, respectively (P = 0.001)], as well as the secondary endpoints total mortality, myocardial infarction and death plus myocardial infarction (RR for the third vs. the first tertile 4.33, 3.25 and 3.46, respectively, P < 0.05). In a multivariable Cox-regression model, AIx@75 added prognostic value above and beyond clinical risk factors, angiographic variables, and medications (RR 1.8, 95%CI 1.18-2.76 per increasing AIx@75-tertile, P < 0.01). CONCLUSION: Increased arterial wave reflections are independently associated with an increased risk for severe short- and long-term cardiovascular events in patients undergoing PCI.

Aged↗

PubMed2003

Arterial stiffness, wave reflections, and the risk of coronary artery disease.

BACKGROUND: Increased arterial stiffness, determined invasively, has been shown to predict a higher risk of coronary atherosclerosis. However, invasive techniques are of limited value for screening and risk stratification in larger patient groups. METHODS AND RESULTS: We prospectively enrolled 465 consecutive, symptomatic men undergoing coronary angiography for the assessment of suspected coronary artery disease. Arterial stiffness and wave reflections were quantified noninvasively using applanation tonometry of the radial artery with a validated transfer function to generate the corresponding ascending aortic pressure waveform. Augmented pressure (AP) was defined as the difference between the second and the first systolic peak, and augmentation index (AIx) was AP expressed as a percentage of the pulse pressure. In univariate analysis, a higher AIx was associated with an increased risk for coronary artery disease (OR, 4.06 for the difference between the first and the fourth quartile [1.72 to 9.57; P<0.01]). In multivariate analysis, after controlling for age, height, presence of hypertension, HDL cholesterol, and medications, the association with coronary artery disease risk remained significant (OR, 6.91; P<0.05). The results were exclusively driven by an increase in risk with premature vessel stiffening in the younger patient group (up to 60 years of age), with an unadjusted OR between AIx quartiles I and IV of 8.25 (P<0.01) and a multiple-adjusted OR between these quartiles of 16.81 (P<0.05). CONCLUSIONS: AIx and AP, noninvasively determined manifestations of arterial stiffening and increased wave reflections, are strong, independent risk markers for premature coronary artery disease.

Aorta↗

PubMed2003

D-dimer in acute aortic dissection.

STUDY OBJECTIVE: Laboratory testing plays a minor role in the assessment of aortic dissection. Its main value is in the exclusion of other diseases. Following an incidental observation, we systematically investigated the relationship between elevated d-dimer levels and acute aortic dissection. DESIGN: We prospectively tested d-dimer levels in patients with suspected acute aortic dissection (10 patients). In addition, we investigated 14 patients who had received a confirmed diagnosis of thoracic aortic dissection during the previous 5 years, in whom d-dimer testing had been performed for differential diagnosis. Thirty-five patients with acute chest pain of other origin served as a control group. SETTING: Tertiary referral hospital. PATIENTS: Twelve patients had type A dissection (Stanford classification), and 12 patients had type B. MEASUREMENTS AND RESULTS: A d-dimer analysis was performed (Tina-quant assay; Roche Diagnostics; Mannheim, Germany) [normal limit of the assay, 0.5 micro g/mL]. The result of the d-dimer test was positive (ie, > 0.5 micro g/mL) in all patients (sensitivity of the test, 100%) with a mean value of 9.4 micro g/mL and a range of 0.63 to 54.7 micro g/mL. The degree of the elevation was correlated to the delay from the onset of symptoms to laboratory testing (mean, 12.6 h; range, 1 to 120 h) and showed a trend to the extent of the dissection, but not to the outcome (14 patients could be discharged; 10 patients died). CONCLUSIONS: Based on our observation, we suggest that testing for d-dimer should be part of the initial assessment of patients with chest pain, especially if aortic dissection is suspected. A negative test result makes the presence of the disease unlikely.

Acute Disease↗