Comparative efficacy and safety of adenosine and regadenoson for assessment of fractional flow reserve: A systematic review and meta-analysis.

BACKGROUND: Adenosine is a coronary hyperemic agent used to measure invasive fractional flow reserve (FFR) of intermediate severity coronary stenosis. AIM: To compare FFR assessment using adenosine with an alternate hyperemic agent, regadenoson. METHODS: PubMed, Google Scholar, CINAHL and Cochrane databases were queried for studies comparing adenosine and regadenoson for assessment of FFR. Data on FFR, correlation coefficient and adverse events from the selected studies were extracted and analyzed by means of random effects model. Two tailed P-value less than 0.05 was considered significant. Heterogeneity was assessed using I 2 test. RESULTS: Five studies with 248 patients were included in the final analysis. All included patients and coronary lesions underwent FFR assessment using both adenosine and regadenoson. There was no significant mean difference between FFR measurement by the two agents [odds ratio (OR) = -0.00; 95% confidence interval (CI): (-0.02)-0.01, P = 0.88]. The cumulative correlation coefficient was 0.98 (0.96-0.99, P < 0.01). Three of five studies reported time to FFR with cumulative results favoring regadenoson (mean difference 34.31 s; 25.14-43.48 s, P < 0.01). Risk of adverse events was higher with adenosine compared to regadenoson (OR = 2.39; 95%CI: 1.22-4.67, P = 0.01), which most commonly included bradycardia and hypotension. Vast majority of the adverse events associated with both agents were transient. CONCLUSION: The performance of regadenoson in inducing maximal hyperemia was comparable to that of adenosine. There was excellent correlation between the FFR measurements by both the agents. The use of adenosine, was however associated with higher risk of adverse events and longer time to FFR compared to regadenoson.

Delayed Presentation During COVID-19 Pandemic Leading to Post-Myocardial Infarction Ventricular Septal Defect.

Post-myocardial infarction ventricular septal defect (post-MI VSD) is a rare complication of ST-elevation myocardial infarction (STEMI) with an incidence of <1% in early revascularization era. Here we present the case of a 66-year-old woman with post-MI VSD owing to delay in her presentation in the current pandemic. Patient presented with worsening back pain and chest pain with confusion, and an EKG positive for inferior wall STEMI. She underwent emergent percutaneous intervention with placement of drug-eluting stent in her right coronary artery. She developed worsening heart failure and new-onset heart murmur and was found to have a VSD on a transthoracic echo. Because of her poor prognosis, family decided to pursue comfort care and patient unfortunately passed. Delay in seeking health care during the pandemic, as seen in our patient, is multifactorial including fear of contracting infection, decreased emergency medical services members, and concerns for overburdening healthcare systems. Lack of standardized in-hospital approach to emergencies while ensuring adequate protection from infection to healthcare workers, especially during the initial phase of the pandemic, led to increased door-to-balloon times in addition to the increased time to first medical contact. The importance of media outreach ensuring availability of health care in emergencies, changing emergency response algorithms to ensure safety of patients and healthcare providers, and including thrombolytic therapy where there is a delay due to stringent screening or delayed COVID-19 testing can be used to prevent worsening complications following STEMI.