SPC365

Cardiopulmonary exercise testing: a complementary tool to assess risk of ventricular arrythmias in Hypertrophic Cardiomyopathy

Session: Sessão de Posters 48 - Risco arrítmico, tomada de decisão e desfechos nas miocardiopatias
Speaker: Daniela Nascimento Pinheiro

Congress: CPC 2026
Topic: F. Valvular, Myocardial, Pericardial, Pulmonary, Congenital Heart Disease
Theme: 17. Myocardial Disease
Subtheme: 17.7 Myocardial Disease - Other
Session Type: Posters Eletrónicos
FP Number: ---
Authors: Daniela Pinheiro; Fernando Nascimento Ferreira; Miguel Marques Antunes; Inês Almeida; Isabel Cardoso; José Viegas; Pedro Brás; Rui Cruz Ferreira; Sílvia Aguiar Rosa

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><strong><span style="font-family:&quot;Calibri&quot;,sans-serif">Introduction</span></strong><span style="font-family:&quot;Calibri&quot;,sans-serif">:&nbsp;Hypertrophic cardiomyopathy (HCM) is linked to an elevated risk of ventricular arrhythmias (VA) and sudden cardiac death (SCD). Cardiopulmonary exercise test (CPET) parameters, including peak oxygen consumption (pVO2) and ventilatory efficiency (VE/VCO2 slope), are currently employed to assess functional capacity, prognosis, and arrhythmic risk.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><strong><span style="font-family:&quot;Calibri&quot;,sans-serif">Aim</span></strong><span style="font-family:&quot;Calibri&quot;,sans-serif">:&nbsp;To evaluate the relationship/association between CPET parameters and VA in HCM patients.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><strong><span style="font-family:&quot;Calibri&quot;,sans-serif">Methods:</span></strong><span style="font-family:&quot;Calibri&quot;,sans-serif">&nbsp;Single-center retrospective study evaluating the association between CPET parameters and VA in HCM patients (pts) who underwent CPET between 2018-2025. Sustained (SVT) or non-sustained ventricular tachycardia (NSVT) was detected via 24-hour holter monitoring, implantable loop recorder or implantable cardioverter-defibrillator (ICD).</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><strong><span style="font-family:&quot;Calibri&quot;,sans-serif">Results:</span></strong> </span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">Sixty-seven consecutive HCM pts underwent CPET (66% male, mean age 57&plusmn;16 years, 19% with obstructive HCM). In a mean follow-up of 69&plusmn;50 months, SVT occurred in 7%, and NSVT in 42%. Pts with NSTV included more females (50% vs 23%, p=0.024) and had a higher extension of late gadolinium enhancement (LGE) (16% vs 9.6%, p=0.049) compared to pts without VAs during follow-up.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">Pts with NSVTs showed a higher VE/VCO2 slope (p=0.006), higher cardiorespiratory optimal point (COP)(p=0.022), and lower maximal heart rate (HR)(p=0.019) compared to patients without VA. </span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">In a univariate regression analysis, a higher VE/VCO2 slope (adjusted OR 1.125, p=0.009), and higher CROP (adjusted OR 1.14, p=0.029) were significantly associated with occurrence of NSVT. The prognostic value of VE/VCO2 slope was confirmed in both submaximal (adjusted OR 1.165, p = 0.041) and maximal (adjusted OR 1.115, p=0.019) exercise testing. The prognostic value of COP was also confirmed for both maximal and submaximal efforts.</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">Maximal HR was significantly associated with NSVTs only in patients with submaximal effort (adjusted OR 0.997, p=0.021).</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">pVO2 did not show a significant association with VAs (p=0.222) nor percent of predicted pVO2 (p=0.117).</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">In a multivariate regression analysis VE/VCO2 slope remained an independent predictor of NSVT even after adjusting for sex, age, genotype, wall thickness, (adjusted OR 1.173, p=0.037), but not for %LGE (p=0.546). This multivariate predictive value was only present during maximal CPET tests, not submaximal (p=0.918).</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><span style="font-family:&quot;Calibri&quot;,sans-serif">ROC curve analysis showed moderate discriminatory ability for VE/VCO2 slope (AUC=0.696, p=0.002, cutoff 28.9). COP was also significant but with lower accuracy (AUC=0.678, p=0.012, cutoff 24.35). ROC curve for pVO2 demonstrated poor discriminatory ability (AUC=0.321).</span></span></span></p>

<p style="text-align:justify"><span style="font-size:12pt"><span style="font-family:&quot;Times New Roman&quot;,serif"><strong><span style="font-family:&quot;Calibri&quot;,sans-serif">Conclusion</span></strong><span style="font-family:&quot;Calibri&quot;,sans-serif">: VE/VCO2 slope was an independent prognostic marker for the prediction of NSVT in patients with HCM, showing a higher predictive value than pVO2 or COP, highlighting the role of CPET as an additional stratification tool for ventricular arrhythmic risk assessment in HCM patients. </span></span></span></p>