Low-risk patients with long QT syndrome may benefit from observational strategy
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An observational strategy focusing on preventive measures was effective in preventing cardiac events in low-risk patients with long QT syndrome, researchers reported.
Ciorsti J. MacIntyre, MD, FRCPC, who was a fellow in genetic cardiology/inherited arrhythmia syndromes at Mayo Clinic at the time of the study and is now an assistant professor of medicine at Queen Elizabeth II Health Sciences Centre, Dalhousie University, Halifax, Nova Scotia, Canada, and colleagues retrospectively analyzed whether intentional nontreatment was appropriate in low-risk asymptomatic patients with long QT syndrome.
From a cohort of 661 patients with long QT syndrome seen at Mayo Clinic, 8.3% (mean age, 38 years; 53% women) had never shown symptoms and were classified as low risk and intentionally untreated. This subset of patients was managed with preventive measures, including avoidance of QT-prolonging drugs, attention to fluid and electrolyte status and use of fever-reduction strategies.
“Intentional nontherapy was chosen together after careful patient evaluation and shared decision-making. Appropriate patient selection after detailed risk assessment and patient education is of paramount importance,” MacIntyre and colleagues wrote. “While intentional nontherapy may be an appropriate, quality of life-improving consideration in low-risk patients, it should not be viewed as an alternative to beta-blockers or more advanced therapies in symptomatic or higher-risk patients.”
Compared with the patients in the treated cohort, who often received beta-blockers and prophylactic implantable cardioverter defibrillators, those in the intentionally untreated cohort were less symptomatic (0% vs. 32%; P < .001), were older at diagnosis (38 years vs. 19 years; P < .001) and had shorter resting QTc values (448 ms vs. 469 ms; P < .001), according to the researchers.
During a mean follow-up of 7.5 years, no patients in the intentionally untreated cohort had a cardiac event triggered by long QT syndrome, and the only death in the cohort during that time was from complications of a glioblastoma, MacIntyre and colleagues wrote.
“Following careful clinical evaluation, risk assessment and institution of prudent precautionary measures such as QT drug avoidance, an observation-only/intentional nontreatment strategy can be considered for very low-risk patients with long QT syndrome,” the researchers wrote. “This clinical profile includes asymptomatic status, older age at diagnosis and QTc below 470 milliseconds. Such low-risk patients realized similarly excellent outcomes but without beta-blocker-associated side effects. At minimum, long QT syndrome patients with this low-risk profile should not receive a prophylactic ICD (which unfortunately continues at disturbing frequency). Amongst highly selected patients, even guideline-recommended/supported beta-blocker therapy may be unnecessary. In such patients, an intentional nontherapy strategy can be considered, particularly when beta-blockers are poorly tolerated or refused by the patient.” – by Erik Swain
Disclosures: MacIntyre reports she received honoraria or speaker fees from Abbott and Medtronic. Please see the study for all other authors’ relevant financial disclosures.
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