Thyrotoxicosis-Induced Cardiogenic Shock: Acute Management Using a Multidisciplinary Approach.

The development of heart failure and cardiomyopathy has been identified as an infrequent but life-threatening complication of thyrotoxicosis or thyroid storm. Thyrotoxicosis-induced cardiomyopathy and cardiogenic shock have been shown to be one of the major causes of sudden mortality in adults. However, the treatment of thyrotoxicosis with non-cardioselective beta-blockers has been implicated in the development of severe decompensation and even cardiogenic shock if cardiac function is not known and often requires a multidisciplinary care team to address it. Here, we have reported the case of a 63-year-old male with a past medical history of hyperthyroidism who presented to the emergency room with persistent shortness of breath. Vital signs were notable for hypotension, tachycardia with an irregular heartbeat, with ECG suggestive of atrial fibrillation with a rapid ventricular rate. The thyroid function test was significant for severely suppressed TSH, and the Burch-Wartofsky Score was >45. The patient rapidly decompensated shortly after being given IV metoprolol, subsequently requiring intubation and pressor support. Two-dimensional (2D) echocardiography (or echo) done afterward was significant for four-chamber dilation with mild global hypokinesis and reduced left ventricular ejection fraction. Endocrinology, Cardiology, and Pulmonary Critical Care teams were consulted to assist in multi-modality management. The administration of a non-cardioselective beta-blocker in decompensated heart failure was suggested as the cause of the rapid deterioration. Through a multi-modality management approach, the patient subsequently improved and was eventually discharged with the resolution of thyroid storm and cardiogenic shock, and with close follow-up with the primary care provider, endocrinologist, and cardiologist. This case illustrates the significance of a multidisciplinary team approach in the acute management of thyrotoxicosis-induced cardiogenic shock, as recommendations from the team were instrumental in helping the patient recover from the acute phase of the illness. Also, this case further highlights the significance of assessing the cardiac function, preferably performing echo before starting the patient on beta-blockers.

Adverse Events Following Transcatheter Edge-to-Edge Repair (TEER) Using MitraClip: Lessons Learned From the Manufacturer and User Facility Device Experience (MAUDE) Registry.

OBJECTIVE: The MitraClip from Abbott is FDA approved intracardiac implantable device for transcatheter edge-to-edge repair (TEER). Despite a few previously published studies, there is limited safety data for its use in clinical practice, hence, we designed this study using data obtained from a safety nationwide database to demonstrate the safety profile of MitraClip. METHODS: The first two of the five authors independently queried all reported adverse events from the United State Food and Drug Administration [FDA] Manufacturer and User Facility Device Experience [MAUDE] registry from January 2014 to December 2020. The primary end point was trend in reported fatal events obtained from this database. The secondary end points included the causes of reported nonfatal reports from the MAUDE registry. The trend of reported fatal events was assessed using the Cochran Armitage trend test over the period of the study. RESULTS: During the study period, subjects included 3370 patients whose MitraClip-associated adverse events were reported and captured by MAUDE registry. Of these, 211 were fatal and 3159 nonfatal events. Fatal event reports resulted deaths and reported nonfatal events were from injuries and device system malfunction. This study demonstrated an initial upward trend from 2014 to 2015 then a subsequent statistically significant downward trend in reported fatal events from 2015 to 2020 (Cochran-Armitage test P = 0.039). The peak proportion of reported fatal events occurred in 2015, (n = 44; representing 1.25% of reported adverse events) and lowest proportion of reported fatal events took place in 2020 (n = 19; representing 0.56% of reported adverse events). The most reported nonfatal events were from malfunctioning of MitraClip system (n = 1170; representing 37% of reported nonfatal events), new unremarkable repolarization abnormalities on periprocedural EKG (n = 864; representing 27% of reported nonfatal events), leaflet rupture (n = 651; representing 21% of reported nonfatal events), and cardiogenic shock (n = 170; representing 5% of reported nonfatal events). CONCLUSIONS: This analysis of the MAUDE Registry indicated, especially within the confines of this study's limitations and poor data quality of information, an apparent downward trend of reported fatal events over the study period. Even though conclusive attributions cannot be made regarding this important finding, perhaps, this points to early evidence of a potential institutional or operator learning curve with this device. However, in view of the inferior quality of the data accrued from the MAUDE Registry, more high-precision studies are needed to better understand these changes, as the utility of MitraClip, becomes more established in clinical practice.

Low Prevalence of Clinically Apparent Cardiac Amyloidosis Among Carriers of Transthyretin V122I Variant in a Large Electronic Medical Record.

BACKGROUND: Transthyretin (TTR) gene mutations are the most common cause of hereditary amyloidosis. Valine replaced by isoleucine in position 122 (V122I) variant is common, particularly in the black population. Carriers of V122I have increased risk for developing cardiac amyloidosis. Despite a relatively high prevalence, the penetrance of V122I is not firmly established. This study sought to determine the prevalence of clinically apparent cardiac amyloidosis among carriers of the TTR V122I variant. METHODS: BioVU, a Vanderbilt University resource linking DNA samples and pre-existing genetic data to de-identified electronic medical records was used to identify TTR V122I mutation carriers. Automated billing code queries (International Classification of Diseases, 9th revision codes), problem list searches, and manual chart reviews were used to identify subjects with clinically diagnosed cardiac amyloidosis. RESULTS: Among 28,429 subjects with available genotype data, 129 were V122I carriers. Carriers had a median age of 42 years (interquartile range 16-64). Noncarriers had a median age of 62 years, (interquartile range 41-77). The carrier rate was 3.7% in blacks and 0.02% in whites. Overall, the prevalence of clinically apparent cardiac amyloidosis was 0.8% in carriers and 0.04% in noncarriers (P = .05). Above age 60, the prevalence of cardiac amyloidosis was 2.6% in carriers and 0.06% in noncarriers (P = .03). CONCLUSION: Carriers of the TTR V122I variant are at a higher risk for development of cardiac amyloidosis, particularly at age>60 years. However, clinically apparent cardiac amyloidosis in this population was uncommon. These results support that the penetrance of TTR V122I is age dependent and suggest it may be significantly lower than previously reported.

Characterization of genome-wide association-identified variants for atrial fibrillation in African Americans.

BACKGROUND: Despite a greater burden of risk factors, atrial fibrillation (AF) is less common among African Americans than European-descent populations. Genome-wide association studies (GWAS) for AF in European-descent populations have identified three predominant genomic regions associated with increased risk (1q21, 4q25, and 16q22). The contribution of these loci to AF risk in African American is unknown. METHODOLOGY/PRINCIPAL FINDINGS: We studied 73 African Americans with AF from the Vanderbilt-Meharry AF registry and 71 African American controls, with no history of AF including after cardiac surgery. Tests of association were performed for 148 SNPs across the three regions associated with AF, and 22 SNPs were significantly associated with AF (P<0.05). The SNPs with the strongest associations in African Americans were both different from the index SNPs identified in European-descent populations and independent from the index European-descent population SNPs (r(2)<0.40 in HapMap CEU): 1q21 rs4845396 (odds ratio [OR] 0.30, 95% confidence interval [CI] 0.13-0.67, P = 0.003), 4q25 rs4631108 (OR 3.43, 95% CI 1.59-7.42, P = 0.002), and 16q22 rs16971547 (OR 8.1, 95% CI 1.46-45.4, P = 0.016). Estimates of European ancestry were similar among cases (23.6%) and controls (23.8%). Accordingly, the probability of having two copies of the European derived chromosomes at each region did not differ between cases and controls. CONCLUSIONS/SIGNIFICANCE: Variable European admixture at known AF loci does not explain decreased AF susceptibility in African Americans. These data support the role of 1q21, 4q25, and 16q22 variants in AF risk for African Americans, although the index SNPs differ from those identified in European-descent populations.

Geographic variations in heart failure hospitalizations among medicare beneficiaries in the Tennessee catchment area.

INTRODUCTION: Although differences in heart failure (HF) hospitalization rates by race and sex are well documented, little is known about geographic variations in hospitalizations for HF, the most common discharge diagnosis for Medicare beneficiaries. METHODS: Using exploratory spatial data analysis techniques, the authors examined hospitalization rates for HF as the first-listed discharge diagnosis among Medicare beneficiaries in a 10-state Tennessee catchment area, based on the resident states reported by Tennessee hospitals from 2000 to 2004. RESULTS: The age-adjusted HF hospitalization rate (per 1000) among Medicare beneficiaries was 23.3 [95% confidence interval (CI), 23.3-23.4] for the Tennessee catchment area, 21.4 (95% CI, 21.4-21.5) outside the catchment area and 21.9 (95% CI, 21.9-22.0) for the overall United States. The age-adjusted HF hospitalization rates were also significantly higher in the catchment area than outside the catchment area and overall, among men, women and whites, whereas rates among the blacks were higher outside the catchment area. Beneficiaries in the catchment area also had higher age-specific HF hospitalization rates. Among states in the catchment area, the highest mean county-level rates were in Mississippi (30.6 ± 7.6) and Kentucky (29.2 ± 11.5), and the lowest were in North Carolina (21.7 ± 5.7) and Virginia (21.8 ± 6.6). CONCLUSIONS: Knowledge of these geographic differences in HF hospitalization rates can be useful in identifying needs of healthcare providers, allocating resources, developing comprehensive HF outreach programs and formulating policies to reduce these differences.