Comparison of Al and Ttr Cardiac Amyloidosis: A Single Center Canadian Experience

Impact of Delayed Diagnosis and Misdiagnosis for Patients with Transthyretin Amyloid Cardiomyopathy (ATTR-CM): A Targeted Literature Review

INTRODUCTION

Transthyretin amyloid cardiomyopathy (ATTR-CM) is a progressive, fatal and under-recognized disease. This targeted literature review assessed the extent and consequences of diagnostic delay and misdiagnosis in ATTR-CM.

METHODS

The Embase database was searched together with proceedings of eight cardiology conferences to identify publications or abstracts on ATTR-CM. Outcomes of interest were time from symptom onset to diagnosis, rates of delayed diagnosis and misdiagnosis, and costs, healthcare resource use or clinical outcomes whilst undiagnosed/misdiagnosed.

RESULTS

Twenty-three articles were included. Weighted means of reported mean and median diagnostic delays were 6.1 and 3.4 years for wild-type (ATTRwt-CM) and 5.7 and 2.6 years for hereditary (ATTRv-CM). Misdiagnosis occurred in 34-57% of patients when reported. Evaluation and misdiagnosis by multiple healthcare providers before receiving an ATTR-CM diagnosis was common, and there was evidence that patients undergo unnecessary or inappropriate evaluations or treatments while misdiagnosed. Diagnostic "red flags" were reported to be underused. Data on the consequences of delay for patients and health systems were sparse, but given the progressive nature of ATTR-CM, delay is likely to have adverse consequences.

CONCLUSION

ATTR-CM patients commonly experience diagnostic delay and misdiagnosis. Efforts are required to provide timely diagnosis so that patients can benefit from earlier access to new disease-modifying therapies.

Seven factors predict a delayed diagnosis of cardiac amyloidosis

INTRODUCTION

Diagnostic delay of cardiac amyloidosis (CAm) continues to challenge clinicians. We investigated features associated with delay and ascertained if a diagnostic delay had negative implications for the patient.

METHODS

We performed a retrospective chart review identifying 82 subjects with biopsy-proven and mass-spectrometry-identified CAm with clinical and epidemiologic data including first potential symptom of amyloidosis. Pathology slides were scored for extent of amyloid. Robust statistical analyses including generalized linear and ordered logistic regression analysis were performed.

RESULTS

There was a 22 month (median) delay in diagnosis, more pronounced (34 months) in subjects with transthyretin (ATTR) amyloidosis. Seven factors predict a delayed diagnosis including ATTR amyloid type (ratio =2.17, 95% CI 1.31-3.59), having carpal tunnel syndrome (2.13, CI 1.49-3.03) and age <70 at first symptom (1.85, CI 1.30-2.61). Individuals with delays of 1+ years had higher levels of NT proBNP (4451 vs. 2559 pg/mL, p = .016) and longer PR intervals (225 vs. 162 ms, p < .001) at the time of diagnosis.

CONCLUSIONS

Diagnostic delays negatively affect cardiac function. Of the predictive clinical features, carpal tunnel syndrome was frequent and its presence should lead to a more aggressive analysis for CAm in the appropriate clinical settings.