Jonah Himelfarb

Objective: The ostium secundum atrial septal defect (ASD) is among the most common congenital cardiac anomalies diagnosed in adulthood. A known complication of transcatheter ASD closure is the development of new-onset atrial fibrillation and flutter (AFi/AFl). These arrhythmias confer an increased risk of postoperative stroke, thrombus formation and systemic emboli. This systematic review examines the burden of de novo AFi/AFl in adults following transcatheter closure and seeks to identify risk factors for AFi/AFl development. Methods: Studies were identified by a search of MEDLINE, EMBASE and Cochrane databases from inception until 29 April 2020. A meta-analysis of AFi/AFl incidence was performed using a random-effects model. Results: A total of 31 studies met inclusion criteria, comprising 4788 adult patients without a history of AFi/AFl. Twenty-three studies were included in quantitative synthesis and demonstrated an overall incidence rate of 1.82 patients per 100 person-years of follow-up (I²=83%). In studies that enrolled only patients ≥60 years old, the incidence was 5.21 patients per 100 person-years (I²=0%). Studies with follow-up duration ≤2 years reported an incidence of 4.05 per 100 person-years (I²=55%) compared with a rate of 1.19 per 100 person-years (I²=85%) for studies with follow-up duration >2 years. Conclusions: The incidence of new-onset AFi/AFl is relatively low following transcatheter closure of secundum ASDs. The rate of de novo AFi/AFl, however, was significantly higher in elderly patients. Shorter follow-up time was associated with a higher reported incidence of AFi/AFl.

Introduction CT use for renal colic has increased costs, radiation exposure and frequently does not alter management. Consequently, choosing wisely (CW) recommends avoiding CT imaging of otherwise healthy patients younger than 50 years presenting with symptoms of recurrent, uncomplicated renal colic. We evaluated the utilisation of CT imaging for this subgroup of patients and subsequently implemented a quality improvement initiative with an aim to reduce unnecessary radiation exposure. Methods A retrospective chart review was performed for all patients younger than 50 years who visited Sunnybrook Health Sciences Centre emergency department (ED) between December 2015 and May 2016 with a discharge diagnosis of renal colic. After the audit period, emergency physicians were engaged to perform a root cause analysis and a driver diagram was developed. In December 2016, a clinical decision tool was introduced to standardise the imaging for patients with presumed renal colic. In May 2017, a separate electronic order was created for low-dose CT for renal colic, including a prompt to remind clinicians of the CW recommendation. The impact of these changes was measured over 15 months. Results Over the initial audit period, 17/63 (27%) of our target population received a CT to rule out renal colic. Many patients received multiple CT scans for renal colic during past ED visits, while one received a total of 13 CTs. At the time of our interventions, the baseline rate of CT scans in our target population was 37%, which reduced to 29% after our project began. Conclusion CT is often used as an initial diagnostic modality for suspected recurrent renal colic despite current guidelines. While this initiative caused only a modest change in management, it led to the introduction of a new low-dose CT scan order specifically to reduce radiation exposure in patients at risk for repeat scans.