Myocardial contrast echocardiography assessment of perfusion abnormalities in hypertrophic cardiomyopathy.

BACKGROUND: Perfusion defects during stress can occur in hypertrophic cardiomyopathy (HCM) from either structural or functional abnormalities of the coronary microcirculation. In this study, vasodilator stress myocardial contrast echocardiography (MCE) was used to quantify and spatially characterize hyperemic myocardial blood flow (MBF) deficits in HCM. METHODS: Regadenoson stress MCE was performed in patients with septal-variant HCM (n = 17) and healthy control subjects (n = 15). The presence and spatial distribution (transmural diffuse, patchy, subendocardial) of perfusion defects was determined by semiquantitative analysis. Kinetic analysis of time-intensity data was used to quantify MBF, microvascular flux rate (ß), and microvascular blood volume. In patients undergoing septal myectomy (n = 3), MCE was repeated > 1 years after surgery.  RESULTS: In HCM subjects, perfusion defects during stress occurred in the septum in 80%, and in non-hypertrophied regions in 40%. The majority of septal defects (83%) were patchy or subendocardial, while 67% of non-hypertrophied defects were transmural and diffuse. On quantitative analysis, hyperemic MBF was approximately 50% lower (p < 0.001) in the hypertrophied and non-hypertrophied regions of those with HCM compared to controls, largely based on an inability to augment ß, although hypertrophic regions also had blood volume deficits. There was no correlation between hyperemic MBF and either percent fibrosis on magnetic resonance imaging or outflow gradient, yet those with higher degrees of fibrosis (≥ 5%) or severe gradients all had low septal MBF during regadenoson. Substantial improvement in hyperemic MBF was observed in two of the three subjects undergoing myectomy, both of whom had severe pre-surgical outflow gradients at rest. CONCLUSION: Perfusion defects on vasodilator MCE are common in HCM, particularly in those with extensive fibrosis, but have a different spatial pattern for the hypertrophied and non-hypertrophied segments, likely reflecting different contributions of functional and structural abnormalities. Improvement in hyperemic perfusion is possible in those undergoing septal myectomy to relieve obstruction.  TRIAL REGISTRATION: ClinicalTrials.gov NCT02560467.

Takotsubo Cardiomyopathy With a Rapidly Resolved Left Ventricular Thrombus.

This article presents the case of a 53-year-old man who presented with acute right superficial femoral and popliteal arterial thrombosis for which he underwent an emergent uncomplicated thrombectomy. He denied preceding cardiovascular or neurologic symptomatology and had no history of coronary or peripheral arterial disease, trauma, hypercoagulability, or malignancy. However, he reported having several days of intense emotional stress prior to presentation. His cardiac exam was normal, his electrocardiogram showed normal sinus rhythm and nonspecific ST-T wave abnormalities, and his troponin levels were normal. Transthoracic echocardiography (TTE) revealed a large (2.4 × 2 cm) apical left ventricle (LV) thrombus, LV apical akinesis, and LV ejection fraction of 40% to 45%. Coronary angiography revealed only luminal irregularities. A repeat TTE performed 3 days after initiating unfractionated heparin revealed complete resolution of the LV thrombus. The patient had an uneventful clinical course and was discharged home in stable condition on oral anticoagulants. The lower incidence of LV thrombus in takotsubo cardiomyopathy (TC) of 1.3% in comparison to 4% to 8% in acute myocardial infarction due to coronary artery disease in the current era of early reperfusion may be explained by the lower extent of ischemic myocardial necrosis associated with TC. This case suggests that the lower extent of myocardial necrosis in TC may also lead to faster resolution of LV thrombus. Therefore, earlier follow-up with TTE (within 2 weeks) and shorter duration of anticoagulation (<3 months) may be considered in patients with TC complicated by LV thrombus formation with or without systemic embolism.

Lambl's Excrescences: Association with Cerebrovascular Disease and Pathogenesis.

BACKGROUND: Lambl's excrescences (LEx) are detected by transesophageal echocardiography (TEE) and are characterized as thin, elongated, and hypermobile structures located at the leaflets' coaptation point of the heart valves. The association of LEx with cerebrovascular disease (CVD) is still undefined and yet patients with LEx and suspected CVD receive unproven effective antiplatelet or anticoagulant therapy or even undergo valve surgery. Also, the association of LEx with aging and atherogenic, inflammatory, or thrombogenic parameters has not been reported. METHODS: Seventy-seven patients with systemic lupus erythematosus (SLE) (71 women, age 37 ± 12 years) and 26 age- and sex-matched healthy controls (22 women, age 34 ± 11 years) prospectively underwent routine history and physical exam, transcranial Doppler, brain MRI, TEE, carotid duplex, and clinical and laboratory evaluations of atherogenesis, inflammation, platelet activity, coagulation, and fibrinolysis. Subjects without stroke/TIA on enrollment (with and without LEx) had a median follow-up of 57 months. RESULTS: On enrollment, 33 (43%) of 77 patients had CVD manifested as acute stroke/TIA (23 patients), cerebromicroembolism by transcranial Doppler (17 patients), or cerebral infarcts by MRI (14 patients). Mitral or aortic valve LEx were equally frequent in healthy controls (46%) as in patients with and without any CVD (39 and 43%), stroke/TIA (35 and 43%), cerebromicroembolism (41 and 42%), or cerebral infarcts (36 and 43%) (all p ≥ 0.72). Also, other mechanisms for CVD other than LEx such as Libman-Sacks vegetations, patent foramen ovale or interatrial septal aneurysm, aortic or carotid atherosclerosis, or thrombogenesis were found in ≥94% of patients with CVD. In addition, 36 subjects with and 44 without LEx had similar low incidence of stroke/TIA (1 (1.3%) and 2 (2.5%), respectively, p = 1.0) during follow-up. Finally, LEx were not associated with aging, atherogenic risk factors, atherosclerosis, inflammation, or thrombogenesis. CONCLUSIONS: In this study, LEx are similarly prevalent in healthy controls and SLE patients, are not associated with CVD, and are not associated with pathogenic risk factors. Therefore, the study findings suggest that LEx may not be cardioembolic substrates, may not represent pathologic valve structures, and may not require therapy.

Successful mortality reduction and control of comorbidities in patients with acromegaly followed at a highly specialized multidisciplinary clinic.

CONTEXT: Acromegaly is usually due to the excessive secretion of GH by a pituitary adenoma. It is frequently accompanied by comorbidities that compromise quality of life and results in elevated mortality rates. OBJECTIVE: To evaluate mortality and morbidity in patients with acromegaly receiving multimodal care. SETTING: Tertiary care center. DESIGN, PATIENTS, AND METHODS: Retrospective evaluation of 442 patients (65.4% women; mean age, 43.5 ± 13.1 y) followed for a median of 6 years (interquartile range [IQR], 3-10). RESULTS: Twenty-two patients died during the study period (4.9%), representing a total standardized mortality ratio (SMR) of 0.72 (95% confidence interval [CI], 0.41-1.03). Standardized mortality ratios were 1.5 and 0.44 for patients whose last GH was above and below 2.5 ng/mL, respectively; 1.17 and 0.16 for those whose last GH was above and below 1 ng/mL, respectively; and 0.94 and 0.46 for those whose last IGF-1 was above and below 1.2 times the upper limit of normal (ULN), respectively. The prevalence of diabetes mellitus, hypertension, heart disease, and cancer was 30%, 35%, 8%, and 4.7%, respectively. The most common cause of death was cancer. On multivariate analysis, diabetes, heart disease, and cancer were related to a baseline GH > 10 ng/mL; the presence of cancer and the last IGF-1 were significant predictors of mortality. Survival decreased as the latest GH levels increased from < 1 ng/mL to > 5 ng/mL and as IGF-1 increased from < 1.2 to > 2 times the ULN. CONCLUSIONS: Mortality in acromegaly can be successfully reduced, provided patients are treated using a multimodal approach with careful management of comorbidities.