Table 2.
Factors Associated With Acute Ischemic Heart Disease and Acute Heart Failure in Adults Hospitalized With Influenza (n = 61 856)*
| Factor | Acute Heart Failure |
Acute Ischemic Heart Disease |
||||
|---|---|---|---|---|---|---|
| Unadjusted Risk Ratio (95% CI) |
Adjusted Prevalence (95% CI) |
Adjusted Risk Ratio (95% CI) |
Unadjusted Risk Ratio (95% CI) |
Adjusted Prevalence (95% CI) |
Adjusted Risk Ratio (95% CI) |
|
| Age group | ||||||
| 18–49 y | Reference | 3.90 (3.39–4.39) | Reference | Reference | 2.07 (1.74–2.39) | Reference |
| 50–64 y | 2.6 (2.28–2.97) | 5.46 (5.04–5.88) | 1.40 (1.22–1.61) | 2.94(2.54–3.41) | 4.12 (3.83–4.59) | 2.04 (1.72–2.43) |
| 65–74 y | 3.51 (3.06–4.01) | 6.17 (5.68–6.66) | 1.58 (1.36–1.84) | 4.45 (3.84–5.16) | 6.04 (5.52–6.56) | 2.93 (2.44–3.51) |
| 75–84 y | 4.63 (4.07–5.28) | 7.31 (6.79–7.82) | 1.88 (1.62–2.18) | 5.55 (4.80–6.41) | 7.07 (6.52–7.63) | 3.43 (2.85–4.12) |
| ≥85 y | 5.95 (5.25–6.73) | 9.04 (8.47–9.62) | 2.32 (2.00–2.70) | 6.84 (5.95–7.86) | 9.02 (8.36–9.68) | 4.37 (3.64–5.25) |
| Sex | ||||||
| Male | Reference | 6.81 (6.48–7.14) | Reference | Reference | 6.43 (6.09–6.76) | Reference |
| Female | 0.89 (0.84–0.95) | 6.74 (6.43–7.05) | 0.99 (0.93–1.06) | 0.77 (0.73–0.82) | 5.56 (5.27–5.86) | 0.87 (0.80–0.93) |
| Race/ethnicity | ||||||
| White, non-Hispanic | Reference | 6.84 (6.56–7.12) | Reference | Reference | 5.83 (5.56–6.09) | Reference |
| Black, non-Hispanic | 0.76 (0.70–0.83) | 6.41 (5.87–6.95) | 0.94 (0.85–1.03) | 0.77 (0.70–0.84) | 6.02 (5.4–6.60) | 1.03 (0.93–1.15) |
| Hispanic | 0.65 (0.57–0.76) | 7.15 (6.10–8.20) | 1.05 (0.90–1.22) | 0.75 (0.65–0.87) | 6.53 (5.42–7.64) | 1.12 (0.94–1.34) |
| Other | 0.82 (0.74–0.90) | 6.74 (6.03–7.45) | 0.99 (0.88–1.10) | 1.06 (0.96–1.16) | 6.46 (5.77–7.15) | 1.11 (0.99–1.25) |
| BMI | ||||||
| Underweight(<18.5 kg/m2) | 0.77 (0.64–0.93) | 5.64 (4.61–6.66) | 0.84 (0.70–1.02) | 0.97 (0.82–1.13) | 6.80 (5.71–7.90) | 1.05 (0.89–1.25) |
| Normal (18.5–24.9 kg/m2) | Reference | 6.68 (6.26–7.10) | Reference | Reference | 6.47 (6.05–6.88) | Reference |
| Overweight (25.0–29.9 kg/m2) | 1.01 (0.92–1.09) | 6.27 (5.87–6.67) | 0.94 (0.86–1.02) | 0.94 (0.86–1.02) | 5.88 (5.47–6.28) | 0.91 (0.83–1.00) |
| Obesity (30.0–39.9 kg/m2) | 1.08 (1.00–1.18) | 7.07 (6.65–7.50) | 1.06 (0.97–1.15) | 0.78 (0.71–0.85) | 5.46 (5.06–5.86) | 0.84 (0.77–0.93) |
| Extreme obesity (≥40.0 kg/m2) | 1.3 (1.18–1.45) | 7.94 (7.19–8.68) | 1.19 (1.06–1.33) | 0.68 (0.60–0.78) | 5.74 (4.95–6.52) | 0.89 (0.76–1.03) |
| Tobacco use | ||||||
| None | Reference | 6.57 (6.24–6.90) | Reference | Reference | 5.62 (5.31–5.94) | Reference |
| Current | 0.86 (0.79–0.94) | 7.70 (7.11–8.30) | 1.17 (1.07–1.28) | 0.98 (0.90–1.08) | 7.47 (6.81–8.13) | 1.33 (1.20–1.48) |
| Previous | 1.41 (1.31–1.51) | 6.66 (6.30–7.03) | 1.01 (0.94–1.09) | 1.37 (1.28–1.48) | 5.82 (5.46–6.18) | 1.03 (0.95–1.13) |
| Medical history† | ||||||
| Atrial fibrillation | 3.49 (3.28–3.71) | 8.56 (8.02–9.10) | 1.40 (1.30–1.52) | 1.95 (1.80–2.11) | 6.32 (5.76–6.88) | 1.08 (0.97–1.19) |
| Chronic heart failure or cardiomyopathy | 11.27 (10.55–12.04) | 20.33 (19.39–21.26) | 8.33 (7.60–9.12) | 3.05 (2.86–3.25) | 10.05 (9.36–10.74) | 2.11 (1.93–2.31) |
| Coronary artery disease | 2.78 (2.62–2.95) | 7.53 (7.11–7.96) | 1.18 (1.10–1.27) | 2.81 (2.64–3.00) | 8.63 (8.08–9.18) | 1.75 (1.61–1.91) |
| Diabetes mellitus | 1.67 (1.58–1.78) | 7.11 (6.73–7.49) | 1.09 (1.01–1.17) | 1.42 (1.33–1.52) | 6.51 (6.11–6.90) | 1.15 (1.06–1.24) |
| Chronic renal disease | 2.53 (2.38–2.69) | 7.73 (7.30–8.16) | 1.22 (1.14–1.32) | 1.93 (1.80–2.07) | 7.00 (6.51–7.49) | 1.25 (1.15–1.36) |
| Influenza vaccination status | ||||||
| Vaccinated | 0.74 (0.69–0.79) | 6.39 (6.11–6.67) | 0.86 (0.80–0.92) | 0.81 (0.75–0.87) | 5.48 (5.21–5.75) | 0.80 (0.74–0.87) |
| Not vaccinated | Reference | 7.44 (7.05–7.83) | Reference | Reference | 6.82 (6.43–7.21) | Reference |
| Antiviral therapy‡ | ||||||
| No treatment | 1.02 (0.93–1.11) | 7.11 (6.50–7.72) | 1.10 (1.00–1.20) | 0.86 (0.78–0.96) | 5.79 (5.14–6.43) | 0.99 (0.88–1.11) |
| Early treatment | Reference | 6.47 (6.22–6.72) | Reference | Reference | 5.86 (5.62–6.10) | Reference |
| Late treatment | 1.64 (1.49–1.79) | 9.25 (8.39–10.10) | 1.43 (1.29–1.58) | 1.3 (1.18–1.44) | 7.56 (6.61–8.32) | 1.27 (1.13–1.44) |
| Influenza type or subtype | ||||||
| B | Reference | 6.67 (6.15–7.18) | Reference | Reference | 5.59 (5.09–6.10) | Reference |
| A(H1N1)pdm09 | 0.77 (0.69–0.86) | 7.22 (6.27–8.17) | 1.08 (0.93–1.26) | 0.73 (0.65–0.83) | 6.38 (5.34–7.42) | 1.14 (0.95–1.37) |
| A(H3N2) | 1.09 (1.00–1.18) | 6.71 (6.39–7.03) | 1.01 (0.92–1.10) | 1.16 (1.06–1.27) | 6.00 (5.69–6.32) | 1.07 (0.96–1.20) |
BMI = body mass index.
Patients were excluded if they were missing BMI, were missing influenza vaccination information, had been treated with influenza antiviral medication >2 d before hospital admission, had an infection that could not be distinguished between influenza type A and B, or were co-infected with A(H1N1)pdm09 and A(H3N2). To adjust for possible confounding by site, we included site as a variable in the model for both acute heart failure and acute ischemic heart disease. The final models for both of these conditions were adjusted for season, surveillance site, age group, sex, race/ethnicity, BMI, tobacco use history, medical history of atrial fibrillation, chronic congestive heart failure or cardiomyopathy, coronary artery disease, diabetes mellitus, chronic renal disease, influenza vaccination status, antiviral therapy, and influenza type or subtype. Regression models were run on each of the 70 imputed data sets and combined using SAS Callable-SUDAAN.
For each medical condition, no history of the condition was used as the reference group.
Antiviral treatment timing was determined relative to the patient's admission date and not the acute cardiovascular event or initial symptom onset.