Arquivos Brasileiros de Cardiologia (Dec 2014)

Late Outcome of a Randomized Study on Oral Magnesium for Premature Complexes

  • Cristina Nádja M. Lima De Falco,
  • Francisco Carlos da Costa Darrieux,
  • Cesar Grupi,
  • Luciana Sacilotto,
  • Cristiano F. Pisani,
  • Sissy Lara,
  • José A. F. Ramires,
  • Eduardo Sosa,
  • Tan Chen Wu,
  • Denise Hachul,
  • Mauricio Scanavacca

DOI
https://doi.org/10.5935/abc.20140171
Journal volume & issue
Vol. 103, no. 6
pp. 468 – 475

Abstract

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Background: Ventricular and supraventricular premature complexes (PC) are frequent and usually symptomatic. According to a previous study, magnesium pidolate (MgP) administration to symptomatic patients can improve the PC density and symptoms. Objective: To assess the late follow-up of that clinical intervention in patients treated with MgP or placebo. Methods: In the first phase of the study, 90 symptomatic and consecutive patients with PC were randomized (double-blind) to receive either MgP or placebo for 30 days. Monthly follow-up visits were conducted for 15 months to assess symptoms and control electrolytes. 24-hour Holter was performed twice, regardless of symptoms, or whenever symptoms were present. In the second phase of the study, relapsing patients, who had received MgP or placebo (crossing-over) in the first phase, were treated with MgP according to the same protocol. Results: Of the 45 patients initially treated with MgP, 17 (37.8%) relapsed during the 15-month follow-up, and the relapse time varied. Relapsing patients treated again had a statistically significant reduction in the PC density of 138.25/hour (p < 0.001). The crossing-over patients reduced it by 247/hour (p < 0.001). Patients who did not relapse, had a low PC frequency (3 PC/hour). Retreated patients had a 76.5% improvement in symptom, and crossing-over patients, 71.4%. Conclusion: Some patients on MgP had relapse of symptoms and PC, indicating that MgP is neither a definitive nor a curative treatment for late follow-up. However, improvement in the PC frequency and symptoms was observed in the second phase of treatment, similar to the response in the first phase of treatment.

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