Somatic mutations of CADM1 in aldosterone-producing adenomas and gap junction-dependent regulation of aldosterone production.

Aldosterone-producing adenomas (APAs) are the commonest curable cause of hypertension. Most have gain-of-function somatic mutations of ion channels or transporters. Herein we report the discovery, replication and phenotype of mutations in the neuronal cell adhesion gene CADM1. Independent whole exome sequencing of 40 and 81 APAs found intramembranous p.Val380Asp or p.Gly379Asp variants in two patients whose hypertension and periodic primary aldosteronism were cured by adrenalectomy. Replication identified two more APAs with each variant (total, n = 6). The most upregulated gene (10- to 25-fold) in human adrenocortical H295R cells transduced with the mutations (compared to wildtype) was CYP11B2 (aldosterone synthase), and biological rhythms were the most differentially expressed process. CADM1 knockdown or mutation inhibited gap junction (GJ)-permeable dye transfer. GJ blockade by Gap27 increased CYP11B2 similarly to CADM1 mutation. Human adrenal zona glomerulosa (ZG) expression of GJA1 (the main GJ protein) was patchy, and annular GJs (sequelae of GJ communication) were less prominent in CYP11B2-positive micronodules than adjacent ZG. Somatic mutations of CADM1 cause reversible hypertension and reveal a role for GJ communication in suppressing physiological aldosterone production.

Long-term relationship between unattended automated blood pressure and auscultatory BP measurements in hypertensive patients.

AIMS: Unattended automated office blood pressure (uAutoOBP) has attracted more attention since SPRINT trial had been published. However, its long-term relationship to attended office blood pressure (AuscOBP) is not known. MATERIAL AND METHODS: Stable treated hypertensive subjects were examined in four Czech academic hypertension centers. All subjects attended four clinical visits three months apart. uAutoOBP was measured with the BP Tru device; AuscOBP was measured three times with auscultatory method by the physician. 24-hour ambulatory blood pressure monitoring (ABPM) was performed within one week from the second clinical visit. RESULTS: Data on 112 subjects aged 65.6 ± 10.8 years with mean AuscOBP 128.2 ± 12.2/78.5 ± 10.3 mm Hg are reported. Across the four clinical visits, the uAutoOBP was by 10.1/3.7 mm Hg lower than AuscOBP and the mean difference was similar during all four visits (P≥.061). Both uAutoOBP and AuscOBP had similar intra-individual variability during study follow-up as demonstrated by similar intraclass correlation coefficients (ICC, for systolic ICC = 0.50, for diastolic ICC = 0.72). However, the intra-individual variability of the systolic AuscOBP and uAutoOBP difference was high as demonstrated by low ICCs for absolute (ICC = 0.17 [95%CI, 0.09 - 0.25]) and low κ coefficients for categorized differences (κ ≤ 0.16). The main determinant of AuscOBP-uAutoOBP difference was AuscOBP level. The AuscOBP-uAutoOBP difference was poor tool to identify hypertension control categories defined on the basis of AuscOBP and ABPM. CONCLUSIONS: Although mean AuscOBP-uAutoOBP differences were relatively similar across the four clinical visits, intra-individual variability of this difference was high. The AuscOBP-uAutoOBP difference was poor tool to identify hypertension control categories defined on the basis of AuscOBP and ABPM. Therefore, uAutoOBP cannot be used as a replacement for ABPM.

In the aftermath of SPRINT: further comparison of unattended automated office blood pressure measurement and 24-hour blood pressure monitoring.

AIMS: Several papers reported that unattended automated office blood pressure (uAutoOBP) is closely related to daytime ambulatory blood pressure monitoring (ABPM). In the present study, we aim to study uAutoOBP and its relation to 24-hour ABPM and ABPM variability. MATERIAL AND METHODS: Stable treated hypertensive subjects were examined in two Czech academic hypertension centres. uAutoOBP was measured with the BP Tru device; attended BP three times with auscultatory method (AuscOBP) by the physician. ABPM was performed within one week from the clinical visit. RESULTS: Data on 98 subjects aged 67.7 ± 9.3 years with 24-hour ABPM 120.3 ± 10.6/72.7 ± 7.9 mm Hg are reported. uAutoOBP was lower than 24-hour (by -5.2 ± 11.3/-0.5 ± 6.9 mm Hg) and daytime (by -6.7 ± 12.82.4 ± 8.0 mm Hg) ABPM and the individual variability of the difference was very large (up to 30 mm Hg). The correlation coefficients between ABPM and uAutoOBP were similar compared to AuscOBP (p ≥ .17). Variability of uAutoOBP, but not AuscOBP, readings during one clinical visit was related to short-term blood pressure variability of ABPM. The difference between AuscOBP and uAutoOBP was larger in patients with white-coat effect compared to other blood pressure control groups (25.1 ± 7.0 vs. 2.2 ± 10.3 mm Hg; p = .0036). CONCLUSIONS: Our study shows that uAutoOBP is not good predictor of ambulatory blood pressure monitoring, not even of the daytime values. It might, however, indicate short-term blood pressure variability and, when compared with AuscOBP, also detect patients with white-coat effect.

A multicentre study on unattended automated office blood pressure measurement in treated hypertensive patients.

AIMS: Unattended automated office blood pressure (uAutoOBP) may eliminate white-coat effect. In the present study, we studied its relationships to attended office blood pressure (BP) and ambulatory BP monitoring (ABPM). MATERIAL AND METHODS: Stable treated hypertensive subjects were examined in four Czech academic hypertension centres. uAutoOBP was measured with the BP Tru device; attended BP was measured six times: three times with auscultatory method (AuscOBP) by the physician followed optionally by three oscillometric measurements (OscOBP). ABPM was performed within one week from the clinical visit. RESULTS: Data on 172 subjects aged 63.7 ± 12.4 years with AuscOBP 127.6 ± 12.1/77.6 ± 10.0 mm Hg are reported. uAutoOBP was by 8.5 ± 9.0/3.0 ± 6.1 mm Hg lower than AuscOBP. The AuscOBP-uAutoOBP difference increased with the AuscOBP level and it did not depend on any other factor. OscOBP differed by 8.6 ± 8.6/1.9 ± 5.7 mm Hg from uAutoOBP. 24-hour mean BP was by 4.2 ± 12.1/3.5 ± 7.8 mm Hg lower than AuscOBP and by 4.3 ± 11.0/0.5 ± 6.9 mm Hg higher than uAutoOBP; the correlation coefficients of 24-hour mean BP with AuscOBP and with uAutoOBP did not differ (p for difference ≥.13). In the lowest BP group (systolic AuscOBP <120 mm Hg or diastolic AuscOBP <70 mm Hg), both AuscOBP and uAutoOBP were lower than 24-hour mean BP, while in the highest BP group (systolic AuscOBP ≥140 mm Hg or diastolic AuscOBP ≥90 mm Hg), they were higher. CONCLUSIONS: Compared to uAutoOBP, attended BP measurement gives higher values, both when measured with auscultatory or oscillometric method. Inter-individual variability of AutoOBP - uAuscOBP difference, as well of uAutoOBP - ABPM difference, is large. We did not prove that uAutoOBP would be associated to 24-hour ambulatory BP more closely than attended BP.

Aldosterone-Producing Adenomas: Histopathology-Genotype Correlation and Identification of a Novel CACNA1D Mutation.

Mutations in KCNJ5, ATP1A1, ATP2B3, CACNA1D, and CTNNB1 are thought to cause the excessive autonomous aldosterone secretion of aldosterone-producing adenomas (APAs). The histopathology of KCNJ5 mutant APAs, the most common and largest, has been thoroughly investigated and shown to have a zona fasciculata-like composition. This study aims to characterize the histopathologic spectrum of the other genotypes and document the proliferation rate of the different sized APAs. Adrenals from 39 primary aldosteronism patients were immunohistochemically stained for CYP11B2 to confirm diagnosis of an APA. Twenty-eight adenomas had sufficient material for further analysis and were target sequenced at hot spots in the 5 causal genes. Ten adenomas had a KCNJ5 mutation (35.7%), 7 adenomas had an ATP1A1 mutation (25%), and 4 adenomas had a CACNA1D mutation (14.3%). One novel mutation in exon 28 of CACNA1D (V1153G) was identified. The mutation caused a hyperpolarizing shift of the voltage-dependent activation and inactivation and slowed the channel's inactivation kinetics. Immunohistochemical stainings of CYP17A1 as a zona fasciculata cell marker and Ki67 as a proliferation marker were used. KCNJ5 mutant adenomas showed a strong expression of CYP17A1, whereas ATP1A1/CACNA1D mutant adenomas had a predominantly negative expression (P value =1.20×10-4). ATP1A1/CACNA1D mutant adenomas had twice the nuclei with intense staining of Ki67 than KCNJ5 mutant adenomas (0.7% [0.5%-1.9%] versus 0.4% [0.3%-0.7%]; P value =0.04). Further, 3 adenomas with either an ATP1A1 mutation or a CACNA1D mutation had >30% nuclei with moderate Ki67 staining. In summary, similar to KCNJ5 mutant APAs, ATP1A1 and CACNA1D mutant adenomas have a seemingly specific histopathologic phenotype.

Serum drug levels to diagnose non-adherence in acute decompensated heart failure.

BACKGROUND: The aim of this study was to analyze medication non-adherence by measuring serum drug levels (SDL) in patients presenting with acute decompensated heart failure (ADHF). METHODS: Included in the study were chronic heart failure patients presenting with signs of acute decompensation. Blood sampling for the measurement of SDL was performed shortly after presentation. SDL were measured using liquid chromatography coupled with mass spectrometry. The estimation of SDL was calculated from the recommended chronic cardiac medications with the exception of drugs administered as part of the acute treatment prior to blood sampling. The patients were labeled as non-adherent when any one of the evaluated medications was not found in the serum. RESULTS: Fifty patients with ADHF were prospectively enrolled. All of the evaluated drugs were detected in the sera of 28 (56%) patients. Non-adherence was diagnosed in the remaining 22 (44%) patients. None of the evaluated medications was detected in the sera of 5 (10%) patients. CONCLUSION: The estimation of SDL indicates that non-adherence to the recommended chronic therapy is a common problem among patients presenting with ADHF. This method should be an essential aspect of routine clinical evaluation in these patients.

Somatic mutations in ATP1A1 and CACNA1D underlie a common subtype of adrenal hypertension.

At least 5% of individuals with hypertension have adrenal aldosterone-producing adenomas (APAs). Gain-of-function mutations in KCNJ5 and apparent loss-of-function mutations in ATP1A1 and ATP2A3 were reported to occur in APAs. We find that KCNJ5 mutations are common in APAs resembling cortisol-secreting cells of the adrenal zona fasciculata but are absent in a subset of APAs resembling the aldosterone-secreting cells of the adrenal zona glomerulosa. We performed exome sequencing of ten zona glomerulosa-like APAs and identified nine with somatic mutations in either ATP1A1, encoding the Na(+)/K(+) ATPase α1 subunit, or CACNA1D, encoding Cav1.3. The ATP1A1 mutations all caused inward leak currents under physiological conditions, and the CACNA1D mutations induced a shift of voltage-dependent gating to more negative voltages, suppressed inactivation or increased currents. Many APAs with these mutations were <1 cm in diameter and had been overlooked on conventional adrenal imaging. Recognition of the distinct genotype and phenotype for this subset of APAs could facilitate diagnosis.

Confirmatory testing in primary aldosteronism: extensive medication switching is not needed in all patients.

OBJECTIVE: Confirmatory testing of suspected primary aldosteronism (PA) requires an extensive medication switch that can be difficult for patients with severe complicated hypertension and/or refractory hypokalemia. For this reason, we investigated the effect of chronic antihypertensive medication on confirmatory testing results. To allow the results to be interpreted, the reproducibility of confirmatory testing was also evaluated. DESIGN AND METHODS: The study enrolled 114 individuals with suspected PA who underwent two confirmatory tests. The patients were divided into two groups. In Group A, both tests were performed on the guidelines-recommended therapy, i.e. not interfering with the renin-angiotensin-aldosterone system. In Group B, the first test was performed on chronic therapy with the exclusion of thiazides, loop diuretics, and aldosterone antagonists; and the second test was performed on guidelines-recommended therapy. Saline infusion, preceded by oral sodium loading, was used to suppress aldosterone secretion. RESULTS: Agreement in the interpretation of the two confirmatory tests was observed in 84 and 66% of patients in Groups A and B respectively. For all 20 individuals in Group A who ever had end-test serum aldosterone levels ≥240 pmol/l, aldosterone was concordantly nonsuppressible during the other test. Similarly, for all 16 individuals in Group B who had end-test serum aldosterone levels ≥240 pmol/l on modified chronic therapy, aldosterone remained nonsuppressible with guidelines-recommended therapy. CONCLUSION: Confirmatory testing performed while the patient is on chronic therapy without diuretics and aldosterone antagonists can confirm the diagnosis of PA, provided serum aldosterone remains markedly elevated at the end of saline infusion.

Comparison of duplex ultrasonography and magnetic resonance imaging in the detection of significant renal artery stenosis.

OBJECTIVE: The aim of our study was to evaluate duplex ultrasonography (DUS) and magnetic resonance angiography (MRA) in detection of haemodynamically significant renal artery stenosis (RAS). METHODS: The study included patients with high clinical suspicion of renovascular hypertension (RVH). The imaging of renal arteries was performed by DUS, MRA and digital subtraction angiography (DSA). Significant RAS was defined as maximum systolic velocity > or =180 cm/sec (DUS) or as 60% reduction of the endoluminal arterial diameter (MRA, DSA). The results of DUS and MRA were assessed in respect to the results of DSA. RESULTS: Arterial supply of 186 kidneys in 94 patients was evaluated. DSA revealed significant RAS in 61 kidneys evaluated. DUS was not able to examine arterial supply in 18 kidneys of 13 patients. In the detection of significant RAS, DUS was characterized by sensitivity and specificity of 85% and 84%. MRA achieved satisfactory imaging quality in all but one kidney evaluated. The sensitivity and specificity of MRA in the detection of significant RAS was 93% and 93%, respectively. CONCLUSION: In patients with high clinical probability of RVH, MRA proved to be more reliable and superior in both sensitivity and specificity to DUS in the detection of significant RAS.

Difficult-to-control arterial hypertension or uncooperative patients? The assessment of serum antihypertensive drug levels to differentiate non-responsiveness from non-adherence to recommended therapy.

Difficult-to-control arterial hypertension is a common medical problem that may result from severe hypertensive disease or from poor adherence to the recommended medical treatment. The identification of non-adherent patients is challenging, especially when non-adherence is intentional. The current report describes the use of serum levels of prescribed antihypertensive drugs to evaluate the adherence in individuals with difficult-to-control arterial hypertension. Serum drug levels (SDLs) were evaluated by liquid chromatography with mass spectrometry. The chromatographic separation was performed on a reversed-phase column with a gradient flow of the mobile phase. The detection of analyzed substances was accomplished on a linear ion-trap mass spectrometer. The subjects were labeled as non-adherent when the serum level of at least one of the evaluated drugs was below the limit of quantification. The study used data from 84 patients with arterial hypertension who underwent SDL assessment to verify compliance with the recommended treatment. Patients who presented with uncontrolled blood pressure despite the recommended combination of at least three antihypertensives were enrolled in the analysis. Based on the evaluation of the SDLs, all of the evaluated drugs were found in the sera of 29 (34.5%) of the study patients. In the remaining 55 (65.5%) patients, non-adherence was diagnosed. None of the prescribed antihypertensive drugs was detected in the sera of the 29 (34.5%) patients. Our data suggest that an assessment of SDLs might be helpful before an extensive evaluation is initiated for difficult-to-control hypertension.

Novel baroreflex activation therapy in resistant hypertension: results of a European multi-center feasibility study.

OBJECTIVES: This study assessed the safety and efficacy of a novel implantable device therapy in resistant hypertension patients. BACKGROUND: Despite the availability of potent antihypertensive drugs, a substantial proportion of patients remain hypertensive. A new implantable device (Rheos system, CVRx, Inc., Minneapolis, Minnesota) that activates the carotid baroreflex may help these patients. METHODS: Forty-five subjects with systolic blood pressure ≥160 mm Hg or diastolic ≥90 mm Hg despite at least 3 antihypertensive drugs were enrolled in a prospective, nonrandomized feasibility study to assess whether Rheos therapy could safely lower blood pressure. Subjects were followed up for as long as 2 years. An external programmer was used to optimize and individualize efficacy. RESULTS: Baseline mean blood pressure was 179/105 mm Hg and heart rate was 80 beats/min, with a median of 5 antihypertensive drugs. After 3 months of device therapy, mean blood pressure was reduced by 21/12 mm Hg. This result was sustained in 17 subjects who completed 2 years of follow-up, with a mean reduction of 33/22 mm Hg. The device exhibited a favorable safety profile. CONCLUSIONS: The Rheos device sustainably reduces blood pressure in resistant hypertensive subjects with multiple comorbidities receiving numerous medications. This unique therapy offers a safe individualized treatment option for these high-risk subjects. This novel approach holds promise for patients with resistant hypertension and is currently under evaluation in a prospective, placebo-controlled clinical trial.

Adrenal venous sampling in primary aldosteronism: a low dilution of adrenal venous blood is crucial for a correct interpretation of the results.

OBJECTIVE: In primary aldosteronism, adrenal venous sampling (AVS) is essential for subtype differentiation as it evaluates aldosterone secretion from both adrenals. Selectivity of adrenal sampling is assessed by the ratio of cortisol concentrations in adrenal venous blood and inferior vena cava blood (C(adrenal)/C(ivc)). Since the criteria for selective adrenal sampling differ among the reported literature, we performed a study to evaluate the influence of different selectivity criteria on AVS results. DESIGN AND METHODS: Reports of AVS were screened retrospectively. All AVS were performed with cosyntrophin infusion. Reports containing samples with C(adrenal)/C(ivc)>or=10 taken from both adrenals and at least one other adrenal sample characterised by C(adrenal)/C(ivc)>or=1.1 were enrolled. For each individual, we chose reference samples that were defined by the highest C(adrenal)/C(ivc) achieved from each adrenal. The significance of the remaining samples with C(adrenal)/C(ivc)>or=1.1 was analysed in regard to their respective reference samples. We assessed the impact of analysed samples on identification of lateralisation of aldosterone secretion that is crucial for decisions concerning adrenalectomy. RESULTS: AVS reports of 87 patients were enrolled. A total of 225 adrenal samples were analysed and divided into five groups according to C(adrenal)/C(ivc):1.1-1.99, 2-2.99, 3-4.99, 5-9.99 and >or=10. By comparing reference with analysed samples, a concordant assessment with respect to lateralisation of aldosterone secretion was observed in 39, 52, 72, 85 and 94% of the respective groups of analysed samples. CONCLUSION: AVS provides consistent information when adrenal samples with high cortisol concentrations are used.

Adrenal venous sampling: where is the aldosterone disappearing to?

Adrenal venous sampling (AVS) is generally considered to be the gold standard in distinguishing unilateral and bilateral aldosterone hypersecretion in primary hyperaldosteronism. However, during AVS, we noticed a considerable variability in aldosterone concentrations among samples thought to have come from the right adrenal glands. Some aldosterone concentrations in these samples were even lower than in samples from the inferior vena cava. We hypothesized that the samples with low aldosterone levels were unintentionally taken not from the right adrenal gland, but from hepatic veins. Therefore, we sought to analyze the impact of unintentional cannulation of hepatic veins on AVS. Thirty consecutive patients referred for AVS were enrolled. Hepatic vein sampling was implemented in our standardized AVS protocol. The data were collected and analyzed prospectively. AVS was successful in 27 patients (90%), and hepatic vein cannulation was successful in all procedures performed. Cortisol concentrations were not significantly different between the hepatic vein and inferior vena cava samples, but aldosterone concentrations from hepatic venous blood (median, 17 pmol/l; range, 40-860 pmol/l) were markedly lower than in samples from the inferior vena cava (median, 860 pmol/l; range, 460-4510 pmol/l). The observed difference was statistically significant (P < 0.001). Aldosterone concentrations in the hepatic veins are significantly lower than in venous blood taken from the inferior vena cava. This finding is important for AVS because hepatic veins can easily be mistaken for adrenal veins as a result of their close anatomic proximity.

Giant renal cyst mimicking ascites on abdominal ultrasonography.

An article describes diagnostic difficulties in patient with giant renal cyst, erroneously diagnosed as ascites on ultrasonographic examination. Patient was initially suspected to have disseminated intraabdominal malignancy. Abdominal paracentesis of supposed ascites was performed. The diagnosis of giant renal cyst was finally made by CT and patient was treated surgically. The limitations of ultrasonographic examination are pointed out are and a brief review of similar cases is given.

Doxazosin: safety and efficacy in the treatment of resistant arterial hypertension.

Five classes of antihypertensive drugs have proven efficacy in the prevention of cardiovascular morbidity and mortality. Among the remaining antihypertensives, the action of alpha-1-blockers is supported by most clinical evidence; however, in combination therapy, the published data concern their use as third-line drugs at the most. The data from patients with drug-resistant hypertension remain limited. The aim of our study was to evaluate the efficacy and safety of doxazosin in this clinical setting. Data from 97 patients with resistant hypertension treated by doxazosin were analysed retrospectively. Doxazosin was usually added as the fifth antihypertensive drug in individuals who were either unresponsive to or intolerant of the combination of other antihypertensives. The dose of doxazosin ranged from 2 to 16 mg/day. The mean duration of follow-up was 21+/-17 months. Adverse events related to doxazosin treatment were rare and led to discontinuation of the therapy in only five patients (5.2%). Data from 34 patients were subjected to analysis of efficacy. In this subgroup, doxazosin therapy led to the reduction of blood pressure from 159+/-20/92+/-14 to 126+/-16/73+/-10 mmHg. We found that doxazosin is a well-tolerated and effective drug for patients with resistant arterial hypertension who require a combination of multiple antihypertensive drugs.

Comparison of magnetic resonance imaging and cardiac catheterization in patients with suspected severe aortic stenosis.

OBJECTIVE: Magnetic resonance imaging (MRI) is a novel technique used in the assessment of aortic stenosis. The aim of the study was to compare MRI and cardiac catheterization (CAT) that is still considered to be a "golden standard" in this indication. METHODS: Thirty-four patients referred to CAT for the evaluation of aortic stenosis were enrolled into the study. CAT was performed according to the standardized protocol. Cardiac output was measured by thermodilution and mean aortic gradient was determined using simultaneous blood pressure measurement in aorta and left ventricle. MRI was performed within the period of 3 weeks after CAT. True FISP sequence with retrospective ECG gating was used for the imaging of the aortic valve orifice. Planimetry of the aortic valve area (AVA) was performed at the time of maximal opening of the valve during systole. RESULTS: MRI enabled the measurement of AVA in all patients enrolled. Mean AVA defined by CAT and MRI were 0,97 (+/- 0,41) cm2 and 1,38 (+/- 0,55) cm2, respectively. The correlation between the evaluated methods was statistically significant (p=0,003), but not very strong (r=0,43). The comparison of both methods in the identification of the severe aortic stenosis was characterized by kappa value of 0,331. CONCLUSION: Our study shows low agreement between cardiac catheterization and magnetic resonance imaging in the assessment of aortic stenosis. However, MRI might have a role in the diagnostic algorithm in patients with suspected severe aortic stenosis and moderate mean aortic gradient or concomitant valvular insufficiency.

Acute hypoxia due to right to left blood shunting in a patient with atrial septal defect.

Acute right to left blood shunt is an unusual cause of acute hypoxia. We describe a case of a patient with an atrial septal defect who developed acute hypoxia due to cardiac tamponade. Acute haemopericardium developed as a complication of temporary transvenous cardiac pacing. Bubble contrast echocardiography confirmed right to left blood shunting at the atrial level. Acute hypoxaemia and the right to left blood shunt resolved when the pericardium was drained. The case underscores the importance of evaluating the presence of an intracardial shunt in patients with otherwise inexplicable hypoxia.

Clinical use of magnetic resonance imaging for the diagnosis of acute myocardial infarction in the survivors of cardiac arrest.

The ventricular arrhythmias with underlying coronary artery disease are a leading cause of sudden cardiac death (SCD). While the SCD survivors with proven AMI are considered to be at low risk of SCD recurrence, those without the evidence of AMI represent a high risk group that benefits from implantable cardioverter defibrillator. Therefore, the evaluation of SCD survivors for the presence of acute myocardial infarction (AMI) as a triggering factor of cardiac arrest is essential. In SCD survivors, the use of the standard diagnostic criteria of AMI may be difficult, as both serum cardiac biomarkers and electrocardiogram can be influenced by previous cardiac arrest. A novel technique that may be used for the diagnosis of AMI is magnetic resonance imaging (MRI). We report its use in four patients after cardiopulmonary resuscitation where the diagnosis of AMI could not be definitely established or excluded by means of other diagnostic procedures.

Contrast-enhanced magnetic resonance and thallium scintigraphy in the detection of myocardial viability: a prospective comparative study.

The aim of the present study was to prospectively compare contrast-enhanced magnetic resonance imaging (CE-MRI) with single-photon emission tomography using (201)Thallium chloride (SPECT Tl) in the detection of myocardial viability. Patients with chronic coronary artery disease and systolic dysfunction defined by an ejection fraction (EF)