Table 3.
Cause-specific hospitalizations in heart failure patients for serum magnesium ≤2 mEq/L
| Cause for hospitalization * | Rate/10,000 person-years follow up (events/follow-up in years) | Rate difference (per 10,000 person-years) † | Matched hazard ratio (95% confidence interval) ‡ | P value | |
|---|---|---|---|---|---|
| Serum magnesium >2 mEq/L (N =560) | Serum magnesium ≤2 mEq/L (N =560) | ||||
| All-cause | 3596 (365/1015) | 4146 (381/919) | + 550 | 1.18 (0.99–1.42) | 0.068 |
| Cardiovascular | 2361 (284/1203) | 2704 (301/1113) | + 343 | 1.14 (0.94–1.39) | 0.182 |
| Worsening heart failure | 995 (147/1478) | 1203 (168/1396) | + 208 | 1.21 (0.94–1.56) | 0.141 |
| Ventricular arrhythmia, cardiac arrest | 119 (20/1678) | 111 (18/1628) | − 8 | 1.00 (0.52–1.92) | 1.000 |
| SV arrhythmias § | 132 (22/1671) | 149 (24/1613) | + 17 | 1.24 (0.65–2.34) | 0.517 |
| AV block, bradyarrhythmia | 18 (3/1699) | 12 (2/1648) | − 6 | 1.00 (0.14–7.10) | 1.000 |
| Suspected digoxin toxicity | 18 (3/1697) | 30 (5/1645) | + 12 | 1.67 (0.40–6.97) | 0.484 |
| Myocardial infarction | 205 (34/1659) | 216 (35/1619) | + 11 | 0.90 (0.54–1.51) | 0.691 |
| Unstable angina | 534 (82/1536) | 498 (75/1506) | − 36 | 0.97 (0.69–1.37) | 0.862 |
| Stroke | 125 (21/1678) | 179 (29/1617) | + 54 | 1.59 (0.87–2.91) | 0.135 |
| Coronary revascularization¶ | 90 (15/1674) | 86 (14/1624) | − 4 | 1.09 (0.48–2.47) | 0.835 |
| Cardiac transplantation | 6 (1/1701) | 30 (5/1646) | + 24 | 5.00 (0.58–42.80) | 0.142 |
| Other cardiovascular ** | 403 (64/1588) | 446 (68/1523) | + 44 | 1.14 (0.78–1.65) | 0.507 |
| Respiratory infection | 241 (40/1657) | 331 (52/1570) | + 90 | 1.34 (0.85–2.12) | 0.206 |
| Other non-cardiovascular | 1201 (167/1391) | 1520 (198/1302) | + 320 | 1.33 (1.04–1.69) | 0.021 |
| Unspecified | 12 (2/1698) | 24 (4/1645) | + 12 | 2.00 (0.37–10.92) | 0.423 |
| Number of hospitalizations | 9714 (986/1015) | 11893 (1093/919) | + 2179 | ||
Data shown include the first hospitalization of each patient due to each cause.
Absolute differences were calculated by subtracting the percentage of patients hospitalized in the low- magnesium group from the percentage of patients hospitalized in the normal magnesium group (before values were rounded).
Hazard ratios and confidence intervals (CI) were estimated from matched Cox proportional-hazards models that used the first hospitalization of each patient for each reason.
Supraventricular (SV) arrhythmias include Atrioventricular (AV) block and bradyarrhythmias
This category includes coronary-artery bypass grafting and percutaneous transluminal coronary angioplasty
This category includes embolism, venous thrombosis, peripheral vascular disease, hypertension, other vascular surgery, cardiac catheterization, other types of catheterization, pacemaker implantation, installation of automatic implantable cardiac defibrillator, electrophysiologic testing, transplant-related evaluation, nonspecific chest pain, atherosclerotic heart disease, hypotension, orthostatic hypotension, and valve operation