Study population and design

Patients planned for elective coronary angiography at the University Hospital of Zurich were screened for eligibility. Clinical examination, thoracic X-ray, serum creatinine analysis, and, in female patients, a pregnancy test were performed. Patients with moderate-to-severe AS and patients with DCM, as determined by echocardiography results, were included (Fig. 1). Patients with suspected coronary artery disease in absence of valvular disease, with preserved left ventricular ejection fraction (LV-EF >40%) [12] and without severe diastolic dysfunction (E/e′ < 15) [13], were included in the control group. Exclusion criteria were catecholamine-dependent cardiogenic shock, respiratory failure requiring the application of positive end expiratory pressure (due to pulmonary edema), atrial fibrillation, atrioventricular conduction abnormalities, slow ventricular tachycardia, kidney failure (glomerular filtration rate <60 ml min⁻¹ [14]), pregnancy, and inability to give informed consent. Included patients underwent elective coronary angiography, during which left ventricular angiography, right heart catheterization, and transpulmonary thermodilution were additionally performed. None of our patients had indirect clinical signs for an aneurysm of the aorta. Directly after angiography, a standardized echocardiography examination was performed. Assignment of patients to the control, AS, and DCM groups was reevaluated based on the echocardiography results obtained during this study. Echocardiography, left and right heart catheter, and transpulmonary thermodilution measurements were compared between the three included patient groups. In addition, patients were divided in two groups of normal or enlarged left ventricular size for comparison of left ventricular end-diastolic volume as determined by left ventricular angiography and GEDVI, as well as two groups of normal or reduced left ventricular function for comparison of left ventricular ejection fraction as determined by left ventricular angiography and GEF and CFI. A left ventricular end-diastolic volume as determined by left ventricular angiography of ≤106 ml in females and ≤150 ml in males and an ejection fraction as determined by left ventricular angiography of >53% in females and >51% in males, were considered normal, respectively [12].

Study design and measurement protocol. Patients planned for elective coronary angiography in a university hospital were included in the study based on the presence of moderate-to-severe aortic valve stenosis or dilated cardiomyopathy in echocardiography. A control group was formed consisting of patients devoid of valvular disease, severe diastolic dysfunction (E/e′ ratio > 15), and reduced LV-EF <40%. During the coronary angiography session, left and right heart catheterization, left ventricular angiography, and transpulmonary thermodilution were performed. AS aortic valve stenosis, DCM dilated cardiomyopathy, LV-EF left ventricular ejection fraction