SPC365

Coronary microvascular dysfunction, myocardial fibrosis and impaired myocardial deformation are associated with supraventricular and ventricular arrhythmic events in hypertrophic cardiomyopathy

Session: CO 21 - Miocardiopatias
Speaker: Silvia Aguiar

Congress: CPC 2021
Topic: F. Valvular, Myocardial, Pericardial, Pulmonary, Congenital Heart Disease
Theme: 17. Myocardial Disease
Subtheme: 17.2 Myocardial Disease – Epidemiology, Prognosis, Outcome
Session Type: Comunicações Orais
FP Number: ---
Authors: Sílvia Aguiar Rosa; Boban Thomas; António Fiarresga; Ana Luísa Papoila; Marta Alves; Inês Cruz; Ricardo Pereira; Gonçalo Branco; Luis Baquero; Rui Cruz Ferreira; Miguel Mota Carmo; Luís Rocha Lopes
<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Background: Coronary microvascular dysfunction (CMD) and fibrosis are two important pathophysiological features in hypertrophic cardiomyopathy (HCM) and have prognostic relevance.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Aim: To assess the impact of CMD and fibrosis on arrhythmic events in HCM patients (P).</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Methods: The study prospectively enrolled HCM P without obstructive epicardial coronary artery disease, who underwent stress cardiovascular magnetic resonance (CMR). CMD was assessed by <span style="background-color:white">perfusion imaging. The myocardium was divided into 32 subsegments (16 AHA segments subdivided into an endocardial and epicardial layer, excluding segment 17) and the ischemic burden was calculated as the number of involved subsegments, assigning 3% of myocardium to each subsegment. </span>Fibrosis was assessed by native T1, extracellular volume (ECV) and LGE. <span style="color:black">Three-dimensional </span><span style="color:black">longitudinal, circumferential and radial strains were analysed.</span><span style="background-color:white"> Atrial fibrillation/flutter (AF/AFL) and non-sustained ventricular tachycardia (NSVT) were documented by 12 lead electrocardiogram and 24hours Holter monitoring. </span>Mixed effects regression models were used and a level of significance &alpha;=0.100 was considered.</span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Results: 75P, 47 (62.7%) male, age 54.6&plusmn;14.8years. 24 P (32.0%) had obstructive HCM, maximal wall thickness (MWT) was 20.1&plusmn;4.6mm, left ventricular (LV) mass 97.2&plusmn;30.5g/m<sup>2</sup>, LV ejection fraction71.6&plusmn;8.3%, ischemic burden <span style="color:#010205">22.5&plusmn;16.0% of LV</span>. <span style="color:#010205">For each unit increased in ischemia (%of LV), there was an increase of 4% in the odds of AF/AFL. Impaired circumferential strain was also associated with AF/AFL (table1). For each unit increased in LGE (% of LV mass), there was an increase of 9.6% in the odds of NSVT. Non obstructive HCM and better radial strain were protective factors for NSVT. There was no relationship between ischemia and NSVT (table1).</span></span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><span style="color:#010205">Conclusion: CMD and consequent ischemia, myocardial fibrosis and impaired myocardial deformation were associated with arrhythmic events in HCM.</span></span></span></p>

<p>&nbsp;</p>

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong><span style="color:#010205">Table 1 Multivariable logistic regression for factors related with arrhythmic events.</span></strong></span></span></p>

<p>&nbsp;</p>

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;OR&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;</strong></span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>95% confidence interval&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; </strong></span></span><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>p-value</strong></span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>AF/AFL</strong></span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Ischemia&nbsp; (% of LV)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1.040&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;1.002 to 1.080&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <strong>&nbsp;</strong>0.039</span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Circumferential strain (%)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1.282&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 1.069 to 1.538&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0.007</span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>NSVT</strong></span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">LGE (% of LV)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1.096&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;1.004 to 1.197&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0.041</span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Non obstructive HCM&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0.196&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0.052 to 0.733&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0.015</span></span></p>

<p><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Radial strain (%)&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0.924&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;0.855 to 1.000&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;&nbsp;&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; 0.049</span></span></p>