COMPARISON OF INTRACORONARY VERAPAMIL VS ADENOSINE FOR RESTORATION OF CORONARY BLOOD FLOW POST PERCUTANEOUS CORONARY INTERVENTION (PCI) IN PATIENTS WITH NO-REFLOW

Objective: To determine the efficacy of intracoronary verapamil vs adenosine in restoration of coronary blood flow, post PCI in patients with No-Reflow. Study Design: Double blind (patient/operator blind) randomized control trial. Place and Duration of Study: Cath lab of AFIC & NIHD Rawalpindi, from Feb 2019 to Aug 2019. Methodology: A total of ninety (n=90) patients of either gender between age 25-80 years of age who underwent angioplasty for STEMI/NSTEMI demonstrating No-Reflow (thrombolysis in myocardial infarction 0,1,2) post PCI were enrolled and were randomized into two groups. Group A received verapamil 500 µg in 10 ml heparinized saline, given slowly over 1 minute and group B received adenosine 60 µg in 10 ml of heparinized saline, given quickly. After the administration of both drugs repeat angiogram was carried out and thrombolysis in Myocardial Infarction flow was assessed. Restoration of blood flow was defined as achievement of thrombolysis in myocardial infarction 3 grade. Results: Efficacy (restoration of thrombolysis in Myocardial Infarction grade 3) was better with intracoronary administration of verapamil when compared with intracoronary administration 2 of adenosine (84.4% vs 80%). The difference was, however, not statistically significant (p=0.581). Conclusion: Efficacy (restoration of thrombolysis in myocardial infarction grade 3) was not statistically significant between intracoronary administration of verapamil and adenosine in no-reflow cases after PCI in patients with STEMI/NSTEMI.

Abstract 16665: Intracoronary Administration of Neonatal Cardiac Mesenchymal Cells Promotes Cardiac Functional Recovery in a Porcine Model of Acute Myocardial Infarction

Background: The strong regenerative potential of neonatal mesenchymal stem cells (nMSCs) in animal MI models when compared to adult MSCs have been attributed to their paracrine secretions. This study determines the therapeutic potential of nMSC-based therapies in a translationally relevant animal large model. Methods: Yorkshire Pigs underwent a 60-minute coronary occlusion followed by reperfusion. Pigs were randomized for intracoronary administration of 10 million nMSCs (n=4), 20 million nMSCs (n=4), 2 mg/kg of TCM (n=4), 10 million nMSCs plus 2 mg/kg TCM (n=5), or placebo (n=4). The infarct size was quantified 48 hours post-infarction. Separate (10 million nMSCs plus 2 mg TCM treated and control) groups were allowed to survive for 28 days, and cardiac MRI (cMR) was performed on post- operative days 7 and 28. Results: After 48hrs, increasing the dose of nMSCs (20 million vs 10 million nMSCs) showed more decrease in infarct size (74+0.03% vs 83.2+0.05%, p =0.25). 2 mg TCM reduced the infarct size in comparison to control (60.8+ 0.09% vs 91+0.03%, p= 0.02). Combination of 10 million nMSCs plus 2 mg TCM achieved the greater reduction of infarct size from 91+ 0.03% to 56+0.02% ( p =0.0002). At 28 days, infarct percent mass to the left ventricle mass was significantly smaller in the combination of 10 million nMSCs and 2mg TCM than control group (3.98+1.7 % vs 13.63 + 3.9%, p =0.003). These combination treated animals showed an increase in stroke volume (+ 10 mL vs - 1.7 mL, p= 0.002) and preserved LV dimensions and ejection fraction by day 28 as compared to day 7. None of the treatment groups showed any end-organ damage. The infarct zone for treated animals showed enhanced angiogenesis and reduced fibrosis, inflammation and apoptosis. Anti-apoptotic signaling molecules related to MAPK pathway are being investigated. Conclusions: Intracoronary infusion of nMSCs-TCM is safe, promotes the strongest cardiac and vascular regeneration by decreasing scar and improving LV function in pigs after AMI. These results provide the rationale for a subsequent translation of a combination allogenic product of nMSCs-TCM to clinical trials.

Does Coronary Microvascular Spasm Exist? Objective Evidence from Intracoronary Doppler Flow Measurements During Acetylcholine Testing

A 43-year-old woman with recurrent atypical angina underwent invasive coronary angiography including intracoronary Doppler blood flow assessment and coronary spasm provocation testing. While obstructive epicardial disease could be ruled-out angiographically, the patient experienced reproduction of her angina symptoms after intracoronary administration of acetylcholine (100 µg) during spasm provocation testing. Simultaneously, the ECG showed new-onset ST-segment depression in the absence of epicardial spasm. In addition, coronary flow velocity was significantly reduced after acetylcholine compared to the baseline condition. Following intracoronary administration of nitroglycerine (200 µg), the patient’s symptoms as well as the ECG changes and coronary flow reduction were reversed. Considering the ongoing challenges in appropriate evaluation of the pathophysiological mechanisms of coronary microvascular dysfunction, simultaneous intracoronary Doppler flow measurement during spasm testing ‐ as shown in this case ‐ may provide objective evidence for microvascular spasm in addition to the standardized diagnostic criteria, especially if they are ambiguous.

P18 The utility and validity of intracoronary administration of nicorandil alone for the measurement of fractional flow reserve in patients with intermediate coronary stenosis

Backgrand Recently, intracoronary nicorandil (ICN) administration in addition to intravenous adenosine 5"-triphosphate (IVATP) is generally used to achieve maximal hyperemia for evaluating fractional flow reserve (FFR). This study investigated the usefulness and safety of ICN alone compared with IVATP and ICN during IVATP for the achievement of maximal hyperemia in patients with suspected angina pectoris. Methods Two-hundred-ten angiographically intermediate lesions in two-hundred-seven patients who underwent FFR assessments were enrolled. FFR was measured after ICN (2mg/5seconds), IVATP (150µg/kg/min) for 2 minutes, IVATP (210µg/km/min) for 2 minutes, and ICN (2mg/5seconds) during IVATP (150µg/kg/min). Maximal hyperemia was defined as the lowest FFR measured among each method. Results During the protocol, 92% of patients achieved maximal hyperemia with ICN2mg, 54% with IVATP 150µg/kg/min, 91% with IVATP 210µg/kg/min, and 99% with ICN2mg during IVATP 150µg/kg/min, respectively. The FFR obtained with ICN2mg were strongly correlated with those obtained with ICN2mg during IVATP150µg/kg/min (r²=0.93, P< 0.001). The mean aortic pressure drop during hyperemia was significantly lower in ICN2mg than in IVATP 150µg/kg/min, IVATP 210µg/kg/min, and ICN2mg during IVATP 150µg/kg/min(9 ± 10, 11 ± 14, 24 ± 17, and 27 ± 19mmHg, p < 0.001, respectively). Despite no side effects reported during hyperemia with ICN2mg alone, transient atrioventricular block was observed in 1(1%) patient with IVATP 150µg/kg/min and 9(4%) patients with IVATP 210µg/kg/min. Also, 20 (10%) patients with IVATP 150µg/kg/min and 56(27%) with IVATP210µg/kg/min experienced chest discomfort during hyperemia. Conclusions The intracoronary administration of NIC2mg is safe and well tolerated, and shortens the procedure. Furthermore, intracoronary NIC2mg produced a more pronounced hyperemia than IVATP and may be the preferred mode of application for the assessment of FFR.