SPC365

Long term beta-blockers after ST-segment elevation myocardial infarction in patients with preserved left ventricular ejection fraction

Session: Sessão de Posters 35 - Enfarte agudo do miocárdio com supra ST
Speaker: Catarina Ribeiro Carvalho

Congress: CPC 2024
Topic: E. Coronary Artery Disease, Acute Coronary Syndromes, Acute Cardiac Care
Theme: 13. Acute Coronary Syndromes
Subtheme: 13.4 Acute Coronary Syndromes – Treatment
Session Type: Cartazes
FP Number: ---
Authors: Catarina Ribeiro Carvalho; Marta Catarina Bernardo; Isabel Martins Moreira; Luís Sousa Azevedo; Ana Baptista; Ilídio Moreira

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>Introduction:</strong> beta-blockers are recommended after acute myocardial infarction (AMI) in patients with left ventricular ejection fraction (LVEF) &le;40% and should be considered in all ACS patients regardless of LVEF. Recent studies showed controversial results regarding the long-term benefits of beta-blocker therapy, namely in the setting of ST-segment elevation myocardial infarction (STEMI) and primary percutaneous coronary intervention.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>Purpose:</strong> to evaluate the prognostic impact of long-term beta-blocker therapy after STEMI in patients with LVEF &gt;40%.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>Methods:</strong> this was a single center retrospective study that included patients with STEMI and LVEF &gt;40%<span style="color:black">, between 2010 and 2016</span>. Patients previously taking beta-blocker or with previous heart failure were excluded. The impact of oral beta-blocker prescription at discharge on the composite endpoint of all-cause mortality, AMI, unplanned revascularization and heart failure (HF) was evaluated.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>Results: </strong>a total of 272 patients were included, 83.1% with beta-blocker prescription. Mean follow-up duration was 6.8&plusmn;2.9 years.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">Apart from being slightly younger than patients without beta-blocker prescription (62.0&plusmn;13.2 vs. 69.0&plusmn;13 years, p=0.001), there were no other significant differences in the baseline characteristics of the two groups, namely regarding LVEF (51.8% vs. 53.7%, p=0.06).</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">The primary endpoint occurred in 82 patients in the beta-blocker group (36.3%) and in 19 patients without beta-blocker prescription (41.3%). Despite the slightly better outcome, beta-blockers didn&rsquo;t seem to significantly reduce the incidence of the composite endpoint (p=0.43). In a multivariate analysis, accounting for possible confounders, only arterial hypertension (HR = 0.57, 95%CI 0.38-0.86) and LVEF (HR = 0.96, 95%CI 0.93-0.99) were independent predictors.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">When analyzing the individual components of the primary endpoint, a subtle trend towards a more favorable outcome in the beta-blocker group was once again observed. However, this was not sufficient to achieve statistical significance in all-cause mortality (13.3% in the beat-blocker group vs. 19.6% in patients without beta-blocker, p=0.25), recurrent AMI (8.4% vs. 10.9%, p=0.51), unplanned revascularization (11.9% vs. 15.2%, p=0.44) or HF (17.7% vs. 21.7%, p=0.47).</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif">The subgroup analysis of patients with mildly reduced LVEF highlighted a further accentuation of the aforementioned differences between groups, yet failed to attain statistical significance. Conversely, these differences were nearly negligible when exclusively assessing the patients with preserved LVEF.</span></span></p>

<p style="text-align:justify"><span style="font-size:11pt"><span style="font-family:Calibri,sans-serif"><strong>Conclusion: </strong>long term use of beta-blocker following STEMI didn&rsquo;t reduce the incidence of the composite endpoint of all-cause mortality, AMI, unplanned revascularization or HF. Nevertheless, in the subgroup of patients with mildly reduced LVEF, a trend toward improved outcomes was identified.</span></span></p>