Comparison of Intracoronary Verapamil and Adenosine for No-Reflow in Normotensive Patients with Acute Coronary Syndrome: A Prospective Observational Study

Objectives: This study aimed to compare the efficacy of intracoronary verapamil versus adenosine in managing the no-reflow phenomenon in normotensive patients with acute coronary syndrome (ACS) undergoing percutaneous coronary intervention (PCI). Methodology: We conducted a prospective observational study at Hayatabad Medical Complex Peshawar from March 2023 to March 2024. A total of 150 normotensive ACS patients scheduled for PCI were enrolled and treated with either intracoronary verapamil (200 µg) or adenosine (48 µg) based on the clinical judgment of the treating cardiologist upon identifying the no-reflow phenomenon. The primary outcomes included improvements in myocardial perfusion, assessed by the achievement of TIMI III flow immediately and at 30 minutes via angiographic analysis. Secondary outcomes assessed were microvascular resistance (IMR), endothelial function (FMD), and the incidence of major adverse cardiac events (MACE) within six months. Results: The verapamil group exhibited a higher percentage of patients achieving TIMI III flow post-treatment compared to the adenosine group (92% vs. 78%, p = 0.03). Both treatment groups demonstrated reductions in IMR (verapamil: 18.5 ± 2.8 units; adenosine: 19.1 ± 3.1 units, p = 0.29) and improvements in FMD (verapamil: 4.1 ± 0.5%; adenosine: 3.9 ± 0.6%, p = 0.15). The incidence of MACE was 18% in the verapamil group and 8% in the adenosine group, indicating comparable safety profiles for both agents. Conclusion: Intracoronary verapamil and adenosine both effectively enhance myocardial perfusion and endothelial function in normotensive ACS patients following PCI. Verapamil showed a slight advantage in achieving TIMI III flow and reducing microvascular resistance, suggesting it may offer superior benefits in specific clinical scenarios. These results support the use of both agents in managing the no-reflow phenomenon, with potential preference for verapamil in particular contexts.