title: Late outcome of a randomized study on oral magnesium for premature complexes.
abstract: 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%.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Instituto do Coração, São Paulo, SP, Brazil.
authors.forename: Cristina Nádja M Lima
authors.initials: CN
authors.lastname: De Falco
authors.affiliation: Instituto do Coração, São Paulo, SP, Brazil.
authors.forename: Francisco Carlos da Costa
authors.initials: FC
authors.lastname: Darrieux
authors.affiliation: Instituto do Coração, São Paulo, SP, Brazil.
authors.forename: Cesar
authors.initials: C
authors.lastname: Grupi
authors.affiliation: Instituto do Coração, São Paulo, SP, Brazil.
authors.forename: Luciana
authors.initials: L
authors.lastname: Sacilotto
authors.affiliation: Instituto do Coração, São Paulo, SP, Brazil.
authors.forename: Cristiano F
authors.initials: CF
authors.lastname: Pisani
authors.affiliation: Instituto do Coração, São Paulo, SP, Brazil.
authors.forename: Sissy
authors.initials: S
authors.lastname: Lara
authors.affiliation: Instituto do Coração, São Paulo, SP, Brazil.
authors.forename: José A F
authors.initials: JA
authors.lastname: Ramires
authors.affiliation: Instituto do Coração, São Paulo, SP, Brazil.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Sosa
authors.affiliation: Instituto do Coração, São Paulo, SP, Brazil.
authors.forename: Tan Chen
authors.initials: TC
authors.lastname: Wu
authors.affiliation: Instituto do Coração, São Paulo, SP, Brazil.
authors.forename: Denise
authors.initials: D
authors.lastname: Hachul
authors.affiliation: Instituto do Coração, São Paulo, SP, Brazil.
authors.forename: Mauricio
authors.initials: M
authors.lastname: Scanavacca
mesh_terms: D000704:Analysis of Variance; D004311:Double-Blind Method; D015716:Electrocardiography, Ambulatory; D006801:Humans; D015990:Placebo Effect; D011761:Pyrrolidonecarboxylic Acid / Q000008:administration & dosage*; D012008:Recurrence; D013997:Time Factors; D016896:Treatment Outcome; D018879:Ventricular Premature Complexes / Q000188:drug therapy*
chemical_list: D011761:Pyrrolidonecarboxylic Acid