Prognostic relevance of left ventricular diastolic function parameters in dilated cardiomyopathy

Patients with dilated cardiomyopathy (DCM) generally have an impaired functional capacity and poor long-term out-comes. A mortality of 5-15% per year has been described actually. Aim of this study was to verify the prognostic relevance of invasive and non-invasive parameters of diastolic function in patients with DCM. In 33 patients with DCM, cardiac catheterization was performed and left ventricular systolic (ejection fraction (EF; %)); left ventricular enddiastolic pressure (LVEDP; mmHg) and diastolic function (time constant of relaxation (T, ms); the constant of myocardial stiffness (b) were derived from biplane laevocardiography and simultaneous micromanometric registration of pressure-volume curves. For evaluation of clinical out-come, the follow-up period was defined as beginning on the day after cardiac catheterization and ending on the most recent date or with a cardiac event (death or cardiac transplantation). All patients were reevaluated for NYHA functional class and completed a standard questionnaire. The following hemodynamic parameters were evaluated: invasive parameters of left ventricular diastolic function (constant of relaxation: tau (ms), constant of myocardial stiffness: b)), as well as parameters of systolic function (ejection fraction (EF; %)), left ventricular pressure (LVEDP; mmHg), left ventricular muscle mass index (LVMMI; g/m2), left ventricular enddiastolic volume index (LVEDVI; ml/m2) and non-invasive parameters of morphological data, left ventricular systolic (fractional shortening (FS, %) and ejection fraction) and diastolic parameters with echocardiography. During the follow-up period of 36 months, 11 of 33 patients experienced a major cardiac event (cardiac death n = 8, heart transplantation n = 3). The major cause of death was progressive pump failure. The remaining 22 patients were further classified with respect to changes in functional status. While clinical symptoms could be improved medically in patients with moderate increase of myocardial stiffness, patients with severe increase of myocardial stiffness (b: 76.1 +/- 12.1 vs 17.9 +/- +8.1, p < 0.001) could not be improved and suffered more cardiac events. Doppler echocardiographic measurements in these patients showed a restrictive filling pattern (VE 0.91 +/- 0.21 vs 0.64 +/- 0.18 m/s; p < 0.01; VA 0.52 +/- 0.23 vs 0.57 +/- 0.24 m/s; p < 0.01, deceleration time 129 +/- 17 vs 211 +/- 14 ms; p < 0.01). The medical heart failure therapy was comparable in both groups. In patients with cardiac events, the diastolic left ventricular variables did not significantly differ between patients who underwent heart transplantation and those who died. Patients who demonstrated a sole impairment of relaxation (tau: > 50 ms) suffered no cardiac events. Impaired diastolic function contributes to the clinical picture of congestive heart failure. Parameters of left ventricular diastolic function are powerful and important predictors of major cardiac events in patients with DCM, like heart transplantation and non-sudden death, and may indicate future clinical success of medical treatment. Invasive and non-invasive parameters of diastolic function reveal comparable information for the estimation of prognosis of patients with DCM in order to initiate early therapy.     

A prospective study on incidence and risk factors of arteriovenous fistulae following transfemoral cardiac catheterization

BACKGROUND: A potentially harmful complication of cardiac catheterization is the arteriovenous fistula. Precise knowledge of possible factors predisposing for acquisition of iatrogenic AV-fistulae could enable cardiologists to perform a risk stratification for cardiac patients prior to catheterization. METHODS: Over a period of 2 years, 10,271 consecutive patients who underwent cardiac catheterization were included in this study. Auscultation of a new femoral bruit was followed by a duplex scan to confirm the suspected diagnosis of an AVF. Every patient was investigated on the day after catheterization. RESULTS: The incidence of iatrogenic AVF was 0.86%. A multivariate regression analysis revealed five significant and independent risk factors: (1) procedural heparin dosage >or=12,500 IU (Odds Ratio (OR)=2.88), (2) coumadin therapy (OR=2.34), (3) puncture of the left groin (OR=2.21), (4) arterial hypertension (OR=1.86) and (5) female gender (OR=1.84). Coronary angioplasty (instead of diagnostic procedure), size and number of sheaths, age and body mass index did not significantly affect the incidence of AVF. CONCLUSIONS: The overall incidence of AV-fistulae following cardiac catheterization approximates 1%. Determination of significant risk factors will facilitate identification of patients at risk for iatrogenic arteriovenous fistulae prior to cardiac catheterization and thus help to develop strategies to reduce the incidence of AV-fistulae.     

The potential benefits of treatment of sleep apnea in heart failure

At least half of patients with heart failure (HF) suffer from sleep apnea. Growing evidence suggests that there may be a strong pathophysiological link between chronic HF and sleep apnea due to nocturnal oxygen desaturation and sympathetic activation. It seems that sleep apnea contributes to systolic and diastolic HF, reduced left and right ventricular function, and arrhythmia (e.g. atrial fibrillation, bradycardia, or ventricular ectopy). Therefore, treatment of sleep apnea might alleviate cardiac symptoms and improve cardiac function. Nevertheless, the exact role of long-term treatment of sleep apnea in HF patients remains to be elucidated, as important clinical endpoints (e.g mortality) have been assessed in only a few studies. Heart Fail Monit 2008;5(4):106-11.     

Intracoronary autologous bone marrow cell transplantation beneficially modulates heart rate variability

Antegrade femoral artery access is commonly used for percutaneous transluminal revascularization of ipsilateral lower limbs in patients with critical limb ischemia. While hemostasis at the end of the procedure can be achieved by manual compression, this may lead to an increase in local vascular complications. Femoral artery closure devices, such as the Angioseal collagen plug and anchor device, have been approved and shown of benefit after retrograde femoral artery catheterization. To date, there are however no data on the use of such arteriotomy closure device after antegrade femoral access. We hereby report a case series of five patients in whom Angioseal was successfully used after antegrade femoral puncture and below-the-knee percutaneous transluminal angioplasty. In all cases the device enabled immediate and complete hemostasis without major complications, despite the intense antithrombotic regimen, including heparin, aspirin, and clopidogrel in all patients, as well as glycoprotein IIb/IIIa inhibitors (in two patients) and fibrinolytic therapy (in one).     

Alterations of left ventricular systolic and diastolic function in pregnant women with insulin-dependent diabetes mellitus

BACKGROUND: During pregnancy, major cardiovascular changes occur. The aim of the following study was to investigate the course of hemodynamic parameters under the increased volume load during pregnancy and delivery in women with insulin-dependent diabetes mellitus. METHODS: We examined 51 pregnant diabetic and 51 healthy pregnant women. The control group consisted of 51 healthy non-pregnant women. In all women, left ventricular mass and fractional shortening were calculated. To evaluate left ventricular diastolic function, mitral inflow and pulmonary venous flow profiles were analyzed. RESULTS: During pregnancy left ventricular mass increased, fractional shortening decreased and diastolic dysfunction was found. While the healthy pregnant women developed signs of disturbed relaxation during pregnancy, pregnant diabetic women showed signs of a disturbed relaxation already at the beginning of gestation. A total of 29 pregnant diabetic women developed a restrictive filling pattern already at the 24th week of gestation. The remaining 22 diabetics had a comparable restrictive filling pattern only during vaginal delivery. In 10 of the 29 pregnant diabetic women dangerous complications were documented, while there were no complications in the healthy pregnant women and the other 22 diabetic pregnant women. CONCLUSIONS: In healthy women pregnancy results in a reversible physiologic left ventricular hypertrophy, a disturbed relaxation pattern and a temporary decrease of left ventricular systolic function. In contrast, pregnant diabetic women demonstrated a delayed relaxation at the beginning of pregnancy and developed a restrictive filling pattern. The early development of a restrictive filling pattern may predispose to complications during delivery in pregnant diabetic women.     

Myocardial collagen type I and impaired left ventricular function under exercise in hypertrophic cardiomyopathy

BACKGROUND: Transaortic subvalvular myectomy (TSM) reduces left ventricular outflow tract gradient and improves symptoms and working capacity in patients with hypertrophic obstructive cardiomyopathy (HOCM). Nevertheless, TSM does not completely restore normal ventricular function, and some patients complain of symptoms despite optimal surgical results. Abnormal myocardial collagen structure in hypertrophic cardiomyopathy might be an indicator of impaired cardiac function. METHODS: Nine patients with HOCM were investigated. Myocytic diameter, collagen volume fraction and light absorbance of immunohistochemically stained collagen subtype I and its product (Coll I(prod)) were measured quantitatively in myectomy specimens. Patients underwent symptom-limited bicycle exercise testing with equilibrium radionuclide angiocardiography to determine ejection fraction (EF). Right heart catheterization was performed simultaneously in order to measure pulmonary capillary wedge pressure (PCWP) as a parameter of global ventricular diastolic filling and cardiac index (CI) as a parameter of functional capacity. RESULTS: Postoperatively, CI increased from 3.1 +/- 0.4 to 5.7 +/- 1.3 l/min/m(2) under exercise. EF was normal at rest (64 +/- 9 %) but did not increase significantly under exercise (66 +/- 14 %). Coll I(prod) (13.62 +/- 7.35 Vv%(prod)) correlated inversely with EF under exercise (r = -0.64; p = 0.05). PCWP increased under exercise from 8 +/- 2 mmHg at rest to 22 +/- 9 mmHg (p = 0.01). Coll I(prod) correlated with PCWP under exercise (r = 0.90; p = 0.001). CONCLUSIONS: Increased collagen subtype I is a predictor of diastolic as well as systolic dysfunction under exercise in patients with HCM after successful TSM.     

The heart in hypertension. III. Determinants of left ventricular hypertrophy and diastolic left ventricular compliance (author's transl)]

Diastolic wall stress and compliance were determined in 74 patients with essential hypertension during diagnostic cardiac catheterization. Ventricular compliance was normal in compensated essential hypertension without coronary artery disease even at severe left ventricular hypertrophy. In contrast, additional coronary stenosis and ventricular dilatation due to cardiac decompensation was asscociated with considerable decrease in ventricular compliance. Thus, left ventricular hypertrophy in essential hypertension does not imply per se a change in ventricular compliance. A decrease in ventricular compliance was followed by a decrease of forward pump function of the left ventricle. whereas ventricular work index (as estimated as the product out of systolic wall stress and the stroke volume) increased. This disproportion between external and internal ventricular work increased with increasing ventricular dilatation and was greatest in decompensated essential hypertension. Accordingly, decompensated essential hypertension had largest ventricular work load and lowest forward pump function in comparison to all other patient groups with essential hypertension. The mass to volume ratio may be considered an important determinant of the degree of left ventricular hypertrophy in essential hypertension. The relationship between the mass to volume ratio and the systolic wall stress may provide a diagnostic and prognostic evaluation of the left ventricle in essential hypertension on the basis of dynamic ventricular geometry.