Cardiac amyloidosis presenting as recurrent acute coronary syndrome with unobstructed coronary arteries: Case report

Chest pain and coronary artery disease in cardiac amyloidosis: Prevalence, mechanisms, and clinical implications

Amyloidosis is a systemic disease affecting multiple organs, and often presents with cardiac involvement, with 2 primary underlying pathologies: amyloid light chain- and transthyretin cardiac amyloidosis. Chest pain can occur in both types with variable clinical presentations. This narrative review describes the relationship between cardiac amyloidosis (CA) and chest pain. A PubMed search (June 03. 2024) identified 393 articles related to chest pain in CA. Twenty-eight studies, in English and with full text, were selected. Articles included were case reports, reviews, perfusion- and autopsy studies. In CA patients 10%-20% report chest pain as the initial symptom preceding the diagnosis, and the overall prevalence of chest pain is 38% of patients with CA and it is related to an increased risk of heart failure hospitalization. The mechanisms leading to chest pain in CA patients include increased left ventricular diastolic pressure, infiltration of amyloid fibrils inside and around coronary arteries, and amyloid compression of the microvasculature. The mechanisms commonly lead to elevations of plasma troponin levels, which are higher in amyloid patients with chest pain compared to amyloid patients without chest pain. Symptomatic treatment of chest pain can be challenging due to the low tolerability of medical therapy and poor outcomes of coronary interventions in alleviating the pain and with a higher rate of complications. Our review underscores the importance of recognizing chest pain as a CA symptom, particularly in the elderly. Persistent troponin elevation without coronary artery disease could indicate CA. Screening-based and longitudinal studies are crucial for understanding the relationship between chest pain and CA. Acknowledging the significance of chest pain in CA may facilitate early intervention and improve patient outcomes.

Cardiac Amyloidosis Mimicking Non-ST-Segment Myocardial Infarction: A Case Report

Cardiac amyloidosis is a rare but increasingly recognized condition characterized by the deposition of amyloid fibrils in cardiac tissue, leading to structural and functional heart impairment. This infiltrative cardiomyopathy often mimics more common cardiac conditions, posing significant diagnostic challenges. Particularly deceptive is its presentation as non-ST-segment elevation myocardial infarction (NSTEMI), where the clinical overlap necessitates considering amyloidosis in differential diagnoses. A 75-year-old male presented with muscle weakness, respiratory infection symptoms, and elevated cardiac enzymes. His history included a recent hospitalization for NSTEMI, with normal coronary angiography. Initial evaluations showed elevated troponin and CRP levels. A comprehensive cardiac assessment revealed a dilated ascending aorta, moderate systolic dysfunction (left ventricular ejection fraction (LV-EF), 47%), and asymmetrical interventricular septal thickening, suggesting hypertrophic cardiomyopathy or amyloidosis. The patient improved and was referred for further specialized care. Cardiac amyloidosis can mimic acute coronary syndrome (ACS), presenting with chest pain and elevated cardiac biomarkers. Differentiation is critical as amyloidosis involves myocardial infiltration by amyloid proteins, leading to restrictive cardiomyopathy. Advanced imaging techniques like cardiac MRI and nuclear scintigraphy are essential for accurate diagnosis and appropriate management, impacting therapeutic strategies and patient outcomes.

Trends in incidence and clinical outcome of non-ST elevation myocardial infarction in patients with amyloidosis in the United States, 2010-2020

Study objective

To assess temporal changes in clinical profile and in-hospital outcome of patients with amyloidosis presenting with non-ST elevation myocardial infarction, NSTEMI.

Design/setting

We conducted a retrospective observational study using the National Inpatient Sample (NIS) database from January 1, 2010, to December 31, 2020.

Main outcomes

Primary outcome of interest was trend in adjusted in-hospital mortality in patients with amyloidosis presenting with NSTEMI from 2010 to 2020. Our secondary outcomes were trend in rate of coronary revascularization, and trend in duration of hospitalization.

Results

We identified 272,896 hospitalizations for amyloidosis. There was a temporal increase in incidence of NSTEMI among patients aged 18-44 years from 15.5 % to 28.0 %, a reverse trend was observed in 45-64 years: 22.1 % to 17.7 %, p = 0.043. There was no statistically significant difference in rate of coronary revascularization from 2010 to 2020; 16.3 % to 14.2 %, p = 0.86. We observed an increased odds of all-cause in-hospital mortality in patients with NSTEMI compared to those without NSTEMI (aOR = 2.2, 95 % CI: 1.9-2.6, p < 0.001) but there was a decrease trend in mortality from 21.5 % to 11.3 %, p = 0.013 for trend. Hospitalization duration was also observed to decreased from 14.1 days to 10.9 days during the study period (p = 0.055 for trend).

Conclusion

In patients with amyloidosis presenting with NSTEMI, there was increased incidence of NSTEMI among young adults, a steady trend in coronary revascularization, and a decreasing trend of adjusted all-cause in-hospital mortality and length of hospitalization from 2010 to 2020 in the United States.

Coronary ectasia in amyloid cardiomyopathy and neuropathy due to the transthyretin mutation c.323A>G

BACKGROUND

atrial fibrillation(AF) is a frequent manifestation of cardiac involvement in genetic and wild-type transthyretin-related familial amyloidosis(TTR-FA). However, ectasia of coronary arteries and ablation for AF have not been reported in TTR-FA.

METHODS AND RESULTS

A 65yo male developed progressive sensori-motor polyneuropathy since age 59y. At age 60y bifascicular block and myocardial thickening were recognised. At age 62y heart failure developed and work-up with cardiac MRI suggested amyloidosis but biopsy was non-informative. Coronary angiography revealed ectasias of the coronary arteries. At age 65y AF developed, neither responding to electrical cardioversion nor ablation. Work-up for polyneuropathy revealed the point mutation c.323A>G (p.His108Arg) in the TTR-gene. Tafamidis was started but did not exhibit a beneficial effect after 7 months.

CONCLUSIONS

TTR-FA may manifest in the coronary arteries with ectasia. Ablation for AF in TTR-FA may be unsuccessful. Tafamidis has been unsuccessful for cardiac or nerve involvement after the first seven months.