Adult Congenital Heart Disease
Jeremy A. Slivnick, MD
Assistant Professor
University of Chicago Medicine
Chicago, Illinois, United States
Aliya Husain, MD
Professor
University of Chicago Medicine, United States
Jeffrey Mueller, DO
Associate Professor
University of Chicago Medicine, United States
Varun Subashchandran, MD
Resident Physician
University of Chicago Medicine, United States
Nazia Alvi, MD
Cardiologist
AMITA Health Medical Group Heart & Vascular Hinsdale
BOURBONNAIS, Illinois, United States
Amit R. Patel, MD
Professor
University of Virginia Health System
Charlottesville, Virginia, United States
Karolina M. Zareba, MD
Associate Professor
The Ohio State University
Columbus, Ohio, United States
Nitasha Sarswat, MD
Assistant Professor
University of Chicago Medicine, United States
Seth Scheetz, MD
Resident Physician
University of Chicago Medicine, United States
Karima Addetia, MD
Associate Professor
University of Chicago Medicine, United States
Jung Kwon, MD
Resident Physician
University of Chicago Medicine, Illinois, United States
Cardiac amyloidosis (CA) is an infiltrative cardiomyopathy, which is most commonly caused by either transthyretin (ATTR-CA) or immunoglobulin light chain (AL-CA) proteins. While on right ventricular (RV) biopsy, amyloid deposition is almost always identified in the myocardial interstitium, a subset of patients is known to also have vascular involvement (Figure 1). Using cardiac magnetic resonance (CMR), we aimed to compare the clinical and cardiac morphology differences between these two distinct histopathologic CA patterns.
Methods:
29 patients (69±8 years, 76% male, 28% white) with RV biopsy-confirmed CA, who underwent CMR examination at 1.5T were retrospectively identified. CA subtype was confirmed using mass spectrometry and separated as having isolated interstitial or combined vascular and interstitial patterns using Congo Red staining. Of the initially identified 40 patients, 11 patients without an identifiable vessel on biopsy were excluded. CMR left ventricular (LV) volumes, LV mass, ejection fraction (LVEF), T1 mapping, and extracellular volume (ECV) were quantified following previously defined methods. Clinical and CMR parameters were compared between patients with and without vascular involvement using t-tests or Chi-squared tests. Significant intergroup differences were subsequently assessed using multivariable analysis.
Results:
While 18 patients had solely an interstitial pattern, 11 patients had a combined interstitial and vascular involvement. AL-CA was significantly more prevalent in those with combined vascular as compared to isolated interstitial patterns (94 vs 9%, p< 0.0001). Overall, the sensitivity and specificity of vascular involvement for AL-CA was 91% and 94% respectively. Patients with combined patterns were younger and more likely to be female (Table 1). With respect to CMR parameters, those with vascular pattern had significantly lower indexed LV mass and higher LVEF. In multivariable analysis, only CA subtype remained significantly associated with histologic CA pattern after controlling for clinical and CMR covariates while LV mass and LVEF were not (Table 2).
Conclusion:
Histopathologic involvement of the myocardial vasculature was strongly associated with AL-CA even after controlling for clinical and CMR covariates. Multiple studies including our own have shown that patients with AL-CA have less adverse cardiac remodeling at the time of diagnosis1,2. One potential hypothesis based on our findings is that vascular involvement may contribute to earlier symptom onset prior to marked LV hypertrophy and dysfunction. Further research is needed to better understand the impact of vascular involvement on microvascular disease, symptoms, and prognosis in AL-CA.