Assessment of the Utility and Impact of IV Magnesium Infusion on Patient Outcomes and Quality of Life in Acute Heart Failure
Creators: Margaryan, Robert
Publisher: name: University of Alberta Library
Year: 2024

<p>Heart failure (HF) is a complex condition which is a growing and lethal public health issue in Canada and internationally. In the last several decades, the number of treatments for HF with reduced ejection fraction, which makes up a large portion of the HF population, has grown. The recommended therapy for HF patients is a combination of medications known as guideline-directed medical therapy or GDMT. However, as HF is a condition characterized by progressive deterioration many individuals who suffer from chronic HF (CHF) experience frequent episodes of acute decompensation leading to hospitalization for worsening HF also known as acute HF (AHF) even though they are being treated with GDMT. Patients are often given intravenous (IV) magnesium during AHF episodes, but little is known about the frequency and pattern of magnesium testing and treatment, and even less is known about the impact of magnesium treatment on patient outcomes and health-related quality of life (QoL). <br>
The main goal of this study was to determine the current patterns of IV magnesium use and its impact on patient outcomes in acute heart failure. An extension of this goal was to develop the foundational research needed for a future study to assess the impact of IV magnesium therapy on QoL. Consequently, we designed a retrospective cohort study that involved the collection and analysis of data from 42,763 patients and 78,957 episodes of emergency department (ED) visits or hospitalization over 8 years to determine the rates and outcomes of magnesium testing, replacement, and hypomagnesemia. Furthermore, we conducted a network meta-analysis and systematic</p>

<p>review to determine what impact, if any, from IV magnesium would justify its continued use, the sample size needed for a sufficiently powered future prospective study, and the effect of different treatment combinations on the QoL of patients with CHF. <br>
Our first study demonstrated that serum magnesium testing occurred in 58.7% of episodes and did not occur more frequently in patients with lower or higher potassium levels. The testing established that 31.7% of all patient episodes were hypomagnesemic and we found that with every 0.02 mmol/L unit decrease in serum magnesium level from 0.7 mmol/L and every 0.02 mmol/L unit increase in serum magnesium level from 0.86 mmol/L the risk of mortality at 2 years from the event increased significantly. This experiment also found that IV magnesium was given in 13.7% of all patient episodes and in those episodes 70.2% of the patients had hypomagnesemia. After overlap weighting, IV magnesium was associated with a higher risk of mortality at 7 and 7-30 days, but not any time points afterward. Patients with normal magnesium levels had the highest risk of mortality after receiving IV magnesium. Our second study showed that a combination of ARNi + BB + MRA + SGLT2i resulted in the largest change in QoL with an effect size of 7.11 units of change, but this effect was not significant. The treatment combination that resulted in the largest improvement in QoL was ARNi + BB + SGLT2i which had an effect size of 5.33. Our study results also showed that the individual therapy that led to the greatest improvement in QoL was SGLT2i with a mean change of 3.37 while the least effective was digoxin with a mean change of -5.34. </p>

<p>We concluded that hypomagnesemia may be associated with worse long-term outcomes for patients with acute heart failure, but it is not clear if this is related to physiological actions of magnesium. Furthermore, our studies showed that IV magnesium is associated with an increased risk of short-term mortality, however, whether this is caused by the administration of IV magnesium is unknown. Our network meta-analysis indicated that accepted combinations of HF treatments resulted had an effect size of 3-7 units in the KCCQ overall summary score and our findings suggest that a study evaluating IV magnesium’s impact on QoL should do so both through a measurement of the mean change of QoL score and through a measurement of the proportion of patients undergoing a small, medium and large clinical change both towards improvement and deterioration of QoL due to the within-group variability in QoL experience.</p>