Desmosterol accumulation in users of amiodarone.

BACKGROUND: Amiodarone is an effective and widely used antiarrhythmic drug with many possible adverse effects including hypercholesterolaemia and hepatotoxicity. OBJECTIVE: Our aim was to evaluate how long-term amiodarone treatment affects cholesterol metabolism. METHODS: The study population consisted of 56 cardiac patients, of whom 20 were on amiodarone (amiodarone + group) and 36 did not use the drug (amiodarone - group). We also studied a control group of 124 individuals selected randomly from the population. Cholesterol metabolism was evaluated by analysis of serum noncholesterol sterols by gas-liquid chromatography and gas chromatography-mass spectrometry. RESULTS: Comparisons of serum lipids and noncholesterol sterols across the three groups showed increased serum triglyceride in users of amiodarone but no statistically significant group differences in total, LDL or HDL cholesterol or serum proprotein convertase subtilisin/kexin type 9 concentrations. Nor did the groups differ in the ratios of cholestanol or plant sterols to cholesterol in serum, suggesting that cholesterol absorption was unaltered. However, all users of amiodarone had very markedly elevated serum desmosterol concentrations: the desmosterol-to-cholesterol ratio (102 × µmol mmol-1 ) averaged 1030.7 ± 115.7 (mean ± SE) in the amiodarone + group versus 82.7 ± 3.4 and 75.9 ± 1.4 in the amiodarone - and the population control groups (P < 0.001), respectively. CONCLUSION: Use of amiodarone was associated with on average 12-fold serum desmosterol concentrations compared with the control groups. This observation is fully novel and suggests that amiodarone interferes with the conversion of desmosterol to cholesterol in the cholesterol synthesis pathway. Whether accumulation of desmosterol plays a role in amiodarone-induced hepatotoxicity deserves to be studied in the future.

Diagnosing isolated cardiac sarcoidosis.

OBJECTIVES: Cardiac sarcoidosis (CS) without clinically apparent extracardiac disease may escape detection because of the poor sensitivity of endomyocardial biopsy (EMB). We set out to analyse our experience of repeated and imaging-guided biopsies in clinically isolated CS. METHODS: We retrospectively reviewed the medical records, laboratory test results, imaging studies and pathological analyses of 74 patients with either histologically proven or clinically probable CS at our institution between January 2000 and December 2010. RESULTS: Fifty-two patients had histologically proven CS, of whom 33 (26 women) had disease that was clinically isolated to the heart. Sarcoidosis was detected in the first EMB in 10 of the 31 patients who underwent biopsy. CS was found by repeated EMBs, targeted by cardiac imaging, in seven additional patients, and 11 patients were diagnosed by sampling 18-F-fluorodeoxyglucose position emission tomography-positive mediastinal lymph nodes at mediastinoscopy. Together, the first biopsy (cardiac or mediastinal lymph node) provided the diagnosis in 34%, the second biopsy in 31% and the third in 22% of biopsied patients with isolated CS. Four (13%) of the remaining diagnosis were made after cardiac transplantation and one in a patient who did not undergo biopsy) at autopsy after sudden cardiac death. CONCLUSIONS: Cardiac sarcoidosis may present without clinically apparent disease in other organs. At least two-thirds of patients remain undiagnosed after a single EMB session. The detection rate can be improved by repeated and imaging-guided cardiac or mediastinal lymph-node biopsies. Nevertheless, false-negative biopsy results remain a problem in CS patients with no apparent extracardiac disease.

Erectile dysfunction as a risk factor for coronary heart disease: implications for prevention.

There is now mounting evidence that erectile dysfunction (ED) is an early predictor of coronary heart disease (CHD). Men presenting with ED but no other cardiovascular symptoms provide an opportunity for the treating physician to test for asymptomatic CHD and to reduce CHD risk factors.

Duration of the haemodynamic action of a 24-h infusion of levosimendan in patients with congestive heart failure.

AIMS: To determine the duration of haemodynamic and neurohormonal action of a 24-h infusion of levosimendan in heart failure. METHODS AND RESULTS: This was a double-blind, parallel group study in patients with New York Heart Association class II to IV heart failure. Twenty-two patients, with left ventricular ejection fraction <35% and pulmonary capillary wedge pressure (PCWP) above 12 mmHg, were randomised to receive either levosimendan (12 microg/kg followed by a continuous infusion of 0.1-0.2 microg/min) or placebo. Invasively measured cardiac output (CO) increased from 4.3 l/min to 5.4 l/min in the levosimendan group at 6 h. PCWP decreased from 20 mmHg to 15 mmHg in response to levosimendan. Echocardiographically measured maximal effect on PCWP occurred after 6 h, whereas CO reached its highest value at 24 h. The estimated duration of the decrease in PCWP was 7-9 days, and in CO was 12-13 days. Plasma NT-proANP and NT-proBNP levels reached their lowest values at days 3 and 2, and the treatment effect was estimated to last 16 and 12 days, respectively. The long-acting haemodynamic responses reflect levels of the active metabolites OR-1896 and OR-1855, maximal metabolite levels occurred at day 3. CONCLUSIONS: Levosimendan infusion achieved a rapid improvement in haemodynamic parameters in patients with congestive heart failure with maximal effects occurring 1-3 days after starting the infusion, effects were sustained for up to at least a week.

Leakage of cardiac troponin I in aortic valve stenosis.

OBJECTIVE: Degeneration and death of cardiomyocytes contribute to the genesis of heart failure (HF) in aortic valve stenosis (AS). We studied whether the ongoing myocyte damage in AS can be detected from circulating cardiac troponin I (cTnI) concentrations. DESIGN AND SETTING: A cross-sectional cohort study in a university hospital. SUBJECTS AND METHODS: We examined 131 adult patients undergoing echocardiography and cardiac catheterization for isolated AS. Blood was sampled from the aortic root and, in a subset of 49 patients, also from the coronary sinus for the determination of cTnI using a sensitive immunoanalysis. RESULTS: Seventy-three patients (56%) had detectable aortic cTnI (> or =5 ng L(-1)) with 30 of them (23% of the total group) having cTnI above the reference limit in healthy subjects (>14 ng L(-1)). Patients with detectable cTnI had a higher prevalence of HF than those with undetectable cTnI (42% vs. 19%, P = 0.004). Plasma cTnI rose from the aorta to the coronary sinus by > or =5 ng L(-1) in 13 of 49 patients with AS (27%) versus in none of 12 control patients free of structural heart disease (P = 0.044). AS patients with transcardiac cTnI gradients > or =5 ng L(-1) had lower left ventricular (LV) ejection fractions than AS patients with gradients <5 ng L(-1) (mean +/- SD, 52 +/- 14% vs. 61 +/- 11%; P = 0.011). CONCLUSIONS: Detectable circulating cTnI is not uncommon in AS and shows a moderate association with the presence of HF. Leakage of cTnI into the coronary sinus associates with impairment of LV systolic function. Monitoring cTnI could provide a means to expose incipient clinical deterioration in AS.

Diagnosing heart failure in aortic valve stenosis.

OBJECTIVE: In aortic valve stenosis (AS), heart failure (HF) omens a high risk of death and is an indication for prompt valve replacement. We studied whether its detection can be facilitated by measuring plasma N-terminal B-type natriuretic peptide (Nt-BNP) or by estimating pulmonary capillary wedge pressure (PCWP) using echocardiography. DESIGN AND SETTING: A cross-sectional cohort study in a university hospital. SUBJECTS AND METHODS: We studied 137 consecutive adult patients referred to our unit for invasive evaluation of isolated AS. All patients underwent cardiac catheterization, measurement of plasma Nt-BNP and estimation of PCWP by Doppler echocardiography of transmitral and pulmonary venous flow velocities. The final diagnosis of HF was based on the combined criteria of dyspnoea on ordinary effort and PCWP >14 mmHg at cardiac catheterization. The performance of Nt-BNP and the PCWP estimate in the detection of HF were studied using receiver operating characteristic (ROC) analysis. RESULTS: Totally 42 patients had HF. A cardiologist's clinical diagnosis of HF had high specificity (94%) but poor sensitivity (66%). With an optimized cut-off point, plasma Nt-BNP had moderate sensitivity (77%) and specificity (79%) for HF; the ROC area was 0.83. The echocardiographic PCWP estimate classified 90% of patients correctly as having normal or truly elevated (>14 mmHg) PCWP. Its sensitivity and specificity for the diagnosis of HF were 80 and 95% respectively; the ROC area was 0.88. With a cut-off point of 12 mmHg, the sensitivity of the PCWP estimate was 85% and specificity, 88%. CONCLUSION: The recognition of HF in patients with AS can be improved by estimating PCWP using Doppler echocardiography of transmitral and pulmonary venous flow velocities.

Testing genetic susceptibility loci for alcoholic heart muscle disease.

BACKGROUND: Although many heavy alcohol users have subclinical alcoholic heart muscle disease, only a very few develop severe dilated cardiomyopathy. Therefore, and because cardiac abnormalities correlate only weakly with the duration or quantity of drinking, individual susceptibility differences may exist. In this work we examined whether common gene variants previously associated with cardiac hypertrophy or altered alcohol metabolism could modify the effects of alcohol on the heart. METHODS: We studied 700 middle-aged male victims of sudden death who underwent a medicolegal autopsy. In addition to routine postmortem examination, the weights and the cavity and wall dimensions of the left and right ventricle were measured. Coronary artery stenoses were determined from a silicone rubber cast of the arteries. Alcohol consumption and cardiovascular risk factors were assessed by a structured interview of the spouse. The following gene polymorphisms were determined by using polymerase chain reaction restriction fragment length polymorphism and solid-phase minisequencing techniques: angiotensin converting enzyme I/D, angiotensin II type 1 receptor 1166A/C, aldosterone synthase -344C/T, alcohol dehydrogenases 2 and 3, acetaldehyde dehydrogenase 2, and cytochrome P-450 2E1 DraI, PstI, RsaI, and MspI. RESULTS: The most consistent effects of alcohol (p < 0.05) were a higher total heart weight and a larger right ventricle size with increasing daily drinking. However, these and other effects of alcohol were statistically fully independent of the studied genotypes. CONCLUSIONS: The gene polymorphisms selected for and analyzed in our study are unlikely to modify the effects of alcohol on the heart. Other unknown factors determine the individual susceptibility to alcoholic heart muscle disease.

Dose dependent but non-linear effects of alcohol on the left and right ventricle.

OBJECTIVE: To assess how left (LV) and right ventricular (RV) size, wall thickness, and mass depend on daily alcohol consumption. Among alcoholics, most common findings have been LV hypertrophy and mild systolic or diastolic dysfunction, accompanied occasionally by ventricular dilatation resembling dilated cardiomyopathy. Although it is commonly agreed that chronic heavy alcohol use is injurious to the heart, the dose-injury relation remains a matter of dispute. DESIGN: Prospective series of 700 Finnish men aged 33-70 years who died out of hospital and underwent a medicolegal necropsy. METHODS AND RESULTS: Data on alcohol use and other risk factors were obtained from the spouse. At necropsy, a transversal slice of the heart was traced on a transparent sheet and analysed later for LV and RV cavity areas and wall thicknesses. Coronary artery stenoses were measured from silicone casts of the arteries. In analyses of all men, daily alcohol dose predicted heart weight (beta = 0.17, p < 0.001) and RV cavity area (beta = 0.14, p = 0.007) independent of body size, age, coronary artery disease, hypertension, diabetes, and smoking. In the subgroup of men free of significant coronary artery disease, LV area averaged (SEM) 11.0 (1.0) cm(2) in men drinking < 12 g/day, 7.7 (0.7) cm(2) in those drinking 72-180 g/day, and 10.0 (0.9) cm(2) in those drinking > 180 g/day (p = 0.054). Very heavy drinking (> 180 g/day) was associated with an increase in RV cavity area (p = 0.005). CONCLUSIONS: The effects of alcohol on the heart in middle aged men are dose dependent but partly non-linear. In the absence of coronary artery disease, LV size shows a U shaped reduction with increasing daily alcohol use accompanied by an increase in RV size with very heavy drinking. These findings question the idea of progressive LV dilatation with increasing alcohol consumption among male victims of sudden death.

Coronary artery disease modifies left ventricular remodelling due to heavy alcohol consumption.

BACKGROUND: Coronary artery disease (CAD) and excessive alcohol use can both damage the myocardium. Their combined effect on the heart muscle has not been characterized. We set out to assess whether the presence of CAD modifies the effects of chronic alcohol consumption on the left ventricular (LV) structure in middle-aged men. METHODS: A postmortem examination was performed on 700 Finnish men (age range, 33-70 years) who experienced a sudden, nonhospital death. A coronary arteriography and measurement of the LV wall thickness, cavity area, and ratio by planimetry of transversal ventricular slices were done at the autopsy. The men were grouped by the most severe coronary artery diameter stenosis (<30%, 30-60%, >60%) and by daily alcohol dose (<12 g, 12-72 g, 72-180 g, >180 g) estimated by a structured interview of their lifetime partner. RESULTS: Analysis by ANCOVA, adjusted for age, body size, smoking, hypertension, and diabetes, showed a statistically significant interaction between the effects of coronary artery stenosis and daily alcohol dose on the LV cavity area (p = 0.037) and on the LV wall thickness/cavity area ratio (p = 0.018). In the group with <30% stenosis, the LV wall thickness/cavity area ratio (mean +/- SEM) increased from 1.6 +/- 0.2 mm/cm2 in men drinking <12 g/day to 6.2 +/- 1.4 mm/cm2 in men drinking 72-180 g/day (p = 0.021). A similar trend was seen in men with 30-60% coronary stenosis (p = 0.32). By contrast, in men with >60% coronary stenosis, the LV wall thickness/cavity area ratio decreased with increasing daily alcohol use from 2.2 +/- 0.3 to 1.4 +/- 0.1 mm/cm2 (p = 0.27). CONCLUSIONS: CAD modulates the effects of alcohol on the heart muscle. Heavy drinking results in concentric LV remodelling in men with no or only mild coronary artery stenoses whereas an opposite trend is seen in men with severe coronary artery obstructions. The mechanism of the interaction remains unknown.

Ultrasonography in the quantification of arterial involvement in Takayasu's arteritis.

OBJECTIVE: To evaluate the accuracy of ultrasonography (US) in the detection and quantification of arterial involvement in Takayasu's arteritis (TA). METHODS: The common carotid and subclavian arteries, and the abdominal aorta of 15 patients with TA were studied by Color Doppler (CD) US and Doppler spectral analysis and compared with angiography. RESULTS: The mean difference (+/-SD) between the percent luminal stenoses measured at angiography and by CD US was 2.0+/-10.3% for the common carotid artery, 4.0+/-23.6% for the subclavian artery and -1.3+/-16.8% for the abdominal aorta. The differences were not statistically significant. However, the agreement of the methods was less than satisfactory as shown by the wide standard deviations. CONCLUSIONS: More efforts are needed to improve the less than optimal agreement of US with angiography regarding the severity of individual stenoses. The technique performs best in the study of carotid arteries.

Baroreflex sensitivity and variants of the renin angiotensin system genes.

OBJECTIVES: Because the renin-angiotensin-aldosterone system (RAS) modifies cardiovascular autonomic regulation, we studied the possible associations between baroreflex sensitivity (BRS) and polymorphism in the RAS genes. BACKGROUND: Wide intersubject variability in BRS is not well explained by cardiovascular risk factors or life style, suggesting a genetic component responsible for the variation of BRS. METHODS: Baroreflex sensitivity as measured from the overshoot phase of the Valsalva maneuver and genetic polymorphisms were examined in a random sample of 161 women and 154 men aged 41 to 61 years and then in an independent random cohort of 29 men and 37 women aged 36 to 37 years. An insertion/deletion (I/D) polymorphism of angiotensin-converting enzyme (ACE), M235T variants of angiotensinogen (AGT) and two diallelic polymorphisms in the gene encoding aldosterone synthase (CYP11B2), one in the promoter (-344C/T) and the other in the second intron, were identified by polymerase chain reaction. RESULTS: In the older population, BRS differed significantly across CYP11B2 genotype groups in women (10.1 +/- 4.5, 8.7 +/- 3.8 and 7.1 +/- 3.2 ms x mm Hg(-1) in genotypes -344TT, CT and CC, respectively, p = 0.003 and 11.1 +/- 4.4, 8.9 +/- 4.1 and 7.5 +/- 3.4 ms x mm Hg(-1) in intron 2 genotypes 1/1, 1/2 and 2/2, respectively, p = 0.002), but not in men. No comparable associations were found for BRS with the I/D polymorphism of ACE or the M235T variant of AGT. In the younger population, BRS was even more strongly related to the CYP11B2 promoter genotype (p = 0.0003). The association was statistically significant both in men (p = 0.015) and in women (p = 0.03). CONCLUSIONS: Common genetic polymorphisms in the aldosterone synthase (CYP11B2) gene is associated with interindividual variation in BRS.

Joint effects of an aldosterone synthase (CYP11B2) gene polymorphism and classic risk factors on risk of myocardial infarction.

BACKGROUND: The -344C allele of a 2-allele (C or T) polymorphism in the promoter of the gene encoding aldosterone synthase (CYP11B2) is associated with increased left ventricular size and mass and with decreased baroreflex sensitivity, known risk factors for morbidity and mortality associated with myocardial infarction (MI). We hypothesized that this polymorphism was a risk factor for MI. METHODS AND RESULTS: We used a nested case-control design to investigate the relationships between this polymorphism and the risk of nonfatal MI in 141 cases and 270 matched controls from the Helsinki Heart Study, a coronary primary prevention trial in dyslipidemic, middle-aged men. There was a nonsignificant trend of increasing risk of MI with number of copies of the -344C allele. However, this allele was associated in a gene dosage-dependent manner with markedly increased MI risk conferred by classic risk factors. Whereas smoking conferred a relative risk of MI of 2.50 (P=0.0001) compared with nonsmokers in the entire study population, the relative risk increased to 4.67 in -344CC homozygous smokers (relative to nonsmokers with the same genotype, P=0.003) and decreased to 1.09 in -344TT homozygotes relative to nonsmokers with this genotype. Similar joint effects were noted with genotype and decreased HDL cholesterol level as combined risk factors. CONCLUSIONS: Smoking and dyslipidemia are more potent risk factors for nonfatal MI in males who have the -344C allele of CYP11B2.

Aldosterone synthase (CYP11B2) polymorphisms and cardiovascular function.

In addition to regulating renal sodium resorption and, thus, intravascular volume, aldosterone may have direct effects on the cardiovascular system. We previously identified a polymorphism (-344C/T) in the promoter of the aldosterone synthase (CYP11B2) gene that affects binding of the SF-1 transcription factor and thus might influence gene expression. We found that, whereas this polymorphism has inconsistent associations with levels of aldosterone secretion and blood pressure, the -344C allele is strongly associated with increased left ventricular size and decreased baroreflex sensitivity in healthy individuals. These physiological parameters are cardiovascular risk factors. Indeed, preliminary studies suggest that the -344C allele is also associated with increased risk of myocardial infarction in high risk dyslipidemic males.

MR gradient echo volumetric analysis of human cardiac casts: focus on the right ventricle.

PURPOSE: Our goal was to assess the utility of different imaging directions in volumetric studies of the heart with MRI, in particular to identify the optimal imaging plane for studies of the right ventricle. METHOD: We examined 12 sets of human four-chamber cadaveric cardiac casts. Gradient echo MRI was performed in four imaging planes: (a) perpendicular to the right ventricular inflow tract; (b) perpendicular to the right ventricular outflow tract; (c) in the left ventricular short axis view; and (d) in the axial view. The volumes of the right ventricle and other cardiac cavities were determined with the method of discs. The true cast volumes were measured with the water displacement technique. The agreement between true and measured volumes and the repeatability of image analysis were determined using the Bland-Altman method. RESULTS: There were no statistically significant differences between the measured and true right ventricular volumes irrespective of the imaging plane. The axial plane gave the smallest mean absolute difference from the true right ventricular volume (3.2 +/-2.2 ml) and also the best repeatability of volume analysis (0.2+/-1.6 ml). However, the other imaging planes performed nearly as well, and the differences across the planes were not statistically significant (p > 0.05). Also, in studies of the left ventricle and left and right atrium, the axial view appeared to give the best results, but differences across the imaging planes remained small. CONCLUSION: The present studies of human cardiac casts suggest that gradient echo MRI is well applicable to right ventricular volume measurements. Imaging the right ventricle in axial planes covering the entire heart gives good agreement with true right ventricular volumes and excellent analysis reproducibility. However, other imaging directions perform nearly as well, and thus selection of the imaging plane may not be of major importance to the accuracy of cardiac volume measurements with MR.

Associations between aldosterone synthase gene polymorphism and the adrenocortical function in males.

OBJECTIVES: Two diallelic polymorphisms, one in the transcriptional regulatory region (promoter) and the other in the second intron, have been identified in the aldosterone synthase (CYP11B2) gene encoding aldosterone synthase, the enzyme catalysing the last steps of aldosterone biosynthesis. We have examined the associations between these genetic variations and adrenocortical function in a cohort of Finnish males. DESIGN: A cross-sectional study. SETTING: Helsinki University Central Hospital, Finland. SUBJECTS: Ninety-two males aged 30-55 years. MAIN OUTCOME MEASURES: Basal adrenocortical function was assessed by measuring urinary excretion of aldosterone and cortisol. Functional activity was determined by responses of several adrenal steroids to dexamethasone suppression followed by ACTH stimulation. Polymerase chain reactions were used to identify the polymorphisms in the CYP11B2 gene. RESULTS: The -344TT genotype group in the CYP11B2 promoter had lower systolic blood pressures (P=0.039), but higher urinary aldosterone excretion (P=0.016), and 11-deoxycortisol responses to ACTH stimulation (P=0.021) than the-344CC genotype group. Urinary aldosterone excretion (P=0.033), 11-deoxycortisol (P=0.026), and aldosterone (P=0.013) responses to ACTH were higher in the intron 2 conversion than the nonconversion genotype groups. CONCLUSIONS: Polymorphisms in or near the aldosterone synthase gene are associated with variations in aldosterone and 11-deoxycortisol production in males. This may modulate the activity of the renin-angiotensin system and thereby contribute to blood pressure regulation.