SPC365

Which ECG features can help us diagnose amyloidosis in patients with restrictive and hypertrophic hearts?

Session: CO 07 - Miocardiopatias Infiltrativas
Speaker: José Lopes De Almeida

Congress: CPC 2021
Topic: F. Valvular, Myocardial, Pericardial, Pulmonary, Congenital Heart Disease
Theme: 17. Myocardial Disease
Subtheme: 17.3 Myocardial Disease – Diagnostic Methods
Session Type: Comunicações Orais
FP Number: ---
Authors: José Lopes De Almeida; m. Ferreira; s. Martinho; m. Cunha; g. Campos; c. Ferreira; j. Rosa; l. Gonçalves
<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:#fcfcfc"><span style="font-family:Calibri,sans-serif"><strong><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">Purpose: </span></span></span></strong><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">ECG patterns suggestive of cardiac amyloidosis (CA) have been described and include low voltage QRS complexes, strain-like repolarization, and AV and interventricular conduction delays. However, these parameters were identified by comparing amyloidosis patients with normal populations, but are shared among other causes of restrictive and hypertrophic cardiopathy. We aimed to evaluate the diagnostic accuracy of various eletrocardiographic (ECG) parameters in a cohort of patients with a high suspicion of CA that went through further testing to either confirm or exclude it.</span></span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:#fcfcfc"><span style="font-family:Calibri,sans-serif"><strong><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">Methods: </span></span></span></strong><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">The study subjects comprised consecutive patients referred to perform diphosphonate scintigraphy for suspected CA between 2018 and 2021 (n=76) and with referencing information of either a restrictive or hypertrophic phenotype. The study population was categorized for analysis into 2 groups: patients with proven CA (n=31) and patients without a final diagnosis of CA after investigation (n=45).</span></span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:#fcfcfc"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif">All patients underwent a complete diagnostic work-up including clinical evaluation diphosphonate (DPD) scintigraphy (Figure), blood counts, serum and urine biochemistry, and serum and urine free light chain assay along with immunofixation electrophoresis. </span></span>&nbsp;</span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:#fcfcfc"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">ECG variables potentially predictive of CA from univariable binaray logistic regression analyses were selected. Categorical variables were compared between groups using chi-squared test and continuous using student t-test.</span></span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:#fcfcfc"><span style="font-family:Calibri,sans-serif"><strong><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">Results:</span></span></span></strong><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333"> 43 patients were referenced to DPD </span></span></span><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif">scintigraphy based on an echocardiogram suggestive of a restrictive phenotype and 33 patients suggestive of an hypertrophic phenotype. Among patients with an hypertrophic phenotype, 14 had severe aortic stenosis.</span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:#fcfcfc"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">The overall prevalence of CA was 41%. 4 patients had AL CA and 31 patients had wild type transthyretin related CA. </span></span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:#fcfcfc"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">16 patients had pacemaker rhythm, 37 had sinus rhythm, 9 1st degree AV block, 9 LBBB, 8 RBBB, 15 left axis deviation, 15 low voltage pattern, 16 any kind of ventricular conduction delay, 13 strain-like repolarization. These were not statistically different between groups. </span></span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:#fcfcfc"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">Mean heart rate was 73 bpm </span></span></span><span style="font-size:12.0pt"><span style="background-color:white"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#4d5156">&plusmn;</span></span></span></span><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">16 and mean QRS was 117ms </span></span></span><span style="font-size:12.0pt"><span style="background-color:white"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#4d5156">&plusmn;</span></span></span></span><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333"> 30 and they were not statistically different between groups.</span></span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:#fcfcfc"><span style="font-family:Calibri,sans-serif"><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">Mean QTc was 445ms </span></span></span><span style="font-size:12.0pt"><span style="background-color:white"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#4d5156">&plusmn; </span></span></span></span><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">34 and was statistically higher in CA group (mean QTc 458 </span></span></span><span style="font-size:12.0pt"><span style="background-color:white"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#4d5156">&plusmn; </span></span></span></span><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">32 in CA group <em>vs </em>438ms </span></span></span><span style="font-size:12.0pt"><span style="background-color:white"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#4d5156">&plusmn;</span></span></span></span><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333"> 32 in non-CA group).</span></span></span>&nbsp; <span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">QTc was associated with the presence of CA in our binary logistic regression model (X2=5.2,p=0.02).</span></span></span></span></span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="background-color:#fcfcfc"><span style="font-family:Calibri,sans-serif"><strong><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">Conclusion: </span></span></span></strong><span style="font-size:12.0pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="color:#333333">QTc duration on ECG was associated with the presence of CA in a population of patients with echocardiographic suspicion for this diagnosis. This variable has the potential to&nbsp;be added to multi-parametric scores for the diagnosis of CA.</span></span></span></span></span></span></p>