The Importance of EKG monitoring in Geriatric Patients at Risk of Polypharmacy – Induced QTc Prolongation
by Amy Vanmali, Pharm.D.
2016 CALTCM Poster Session Winner

Polypharmacy has become a potential risk factor for QT prolongation in our aging population leading to increased risk of Torsades de Pointes. According to the Agency for Healthcare Research and Quality, 543,000 adults over the age of 65 were hospitalized for an irregular heartbeat in 2009. The core of this Quality Assurance study was to identify the impact of pharmacist recommendations on polypharmacy-induced QTc prolongation, as measured by a reduction in QTc interval, in elderly patients at a skilled nursing facility.  This study was a retrospective chart review performed for all patients in one skilled nursing facility, taking two or more QTc prolonging medications with: 1) at least one being an atypical antipsychotic; 2) QTc interval greater than 450 msec; 3) age >70 years, and 4) pharmacist recommendation for dose reduction, change in therapy or discontinuation of an offending agent.

Only four patients met the inclusion criteria. Many patients were excluded due to the absence of electrocardiograms (EKG) initially or in follow-up after starting medications that affect QTc interval.  Therefore, a sub-analysis of 31 patients taking 2 or more QTc prolonging medications revealed that 45% of these patents at risk did not have a baseline EKG. There were nine patients with elevated QTc intervals  (> 450 msec) with an average age of 92 years, eight patients with normal EKG results and an average age of 87 years, and 14 patients with no baseline EKGs with an average age of 97 years.  Age was not found to be statistically significant with EKG elevations.  However, since the oldest group (97 years) did not have EKGs; it may have related to the family not wanting any tests, but this study did not evaluate this factor.

Due to the lack of follow-up EKGs, there is the potential for developing a protocol under which pharmacists can order (or at least request) EKGs for medication monitoring purposes and follow up with appropriate recommendations with provider’s support. Future studies should account for additional risk factors for QTc prolongation and careful monitoring of EKGs before and after administration of drugs with anticipated QTc Interval prolongation risk to maximize patient safety.

Acknowledgements: Janice Hoffman, PharmD, Diana Hyun, PharmD, Bob Shmaeff R.Ph, Rick Smith MD and the staff at Los Angeles Jewish Home for the Aging.

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