1. Clinical characteristics of geriatric patients who experiencing AMI and those who without AMI during CAP hospitalization
There were 5111 patients in the respiratory ward and 1095 patients in geriatrics ward hospitalized for CAP and aged ≥ 65 years. 159(3.1%) experienced AMI during hospitalization in respiratory ward and 77(7.0%) in geriatrics ward. A total of 236 patients developed AMI among the 6206 geriatric patients, the overall incidence of AMI in geriatric patients during CAP hospitalization in our study was 3.8%. Among patients who experienced AMI in geriatrics ward, 58 (75.3%) had a non-ST segment elevation myocardial (NSTEMI), on the other hand, this was unclear due to incomplete data in the respiratory ward.
The clinical characteristics of geriatric patients who experiencing AMI and those who without AMI during CAP hospitalization are shown in Table 1. Comparison to patients without AMI, whether in respiratory ward or geriatrics ward, those geriatric patients with AMI during CAP hospitalization were older (P < 0.001, P < 0.001, respectively) and showed a higher prevalence of respiratory failure (P = 0.001, P = 0.021, respectively) and required ventilator use (P < 0.001, P = 0.001, respectively),had longer hospital stays ( P = 0.023, P = 0.030, respectively) Additionally, a high proportion of patients presenting chief complaint of chest pain (P = 0.030, P = 0.004, respectively), heart rate ≥ 125 bpm (P < 0.001, P = 0.015, respectively), BUN ≥ 7 mmol/L (P < 0.001, P < 0.001, respectively), PLT < 10.0 × 109/L (P < 0.001, P = 0.002, respectively), serum sodium < 130 mmol/L (P < 0.001, P = 0.011, respectively), blood glucose ≥ 14 mmol/L (P < 0.001, P = 0.034, respectively) on hospital admission and longer length of hospital stay was observed in elderly patients with AMI both in respiratory ward and geriatrics ward. Moreover, we noted that there were a higher percentage of males (P = 0.001), preexisting coronary artery disease (P < 0.001), hypertension (P = 0.001), hypercholesterolemia (P < 0.001), chronic heart failure (P = 0.003), cerebrovascular disease (P = 0.001), chief complaint of dyspnea (P < 0.001), abnormal blood pressure (P < 0.001) or body temperature (P = 0.003) on admission in elderly patients with AMI during CAP hospitalization in the respiratory ward. While, the proportions of patients who had impaired consciousness (P < 0.001), respiratory rate ≥ 30/min (P = 0.028), abnormal white blood cell count (P < 0.001) and PH < 7.35 (P = 0.001) was higher in patients who experiencing AMI compared with those who without AMI during hospitalized for CAP in the geriatrics ward.
Table 1
Clinical characteristics of geriatric patients who experiencing AMI and those who without AMI during CAP hospitalization
Characteristic
|
Patients in respiratory ward, n = 5111
|
Patients in geriatrics ward, n = 1095
|
|
AMI,n = 159
|
Without AMI,n = 4952
|
P value*
|
AMI, n = 77
|
Without AMI,n = 1018
|
P value*
|
Age, years
|
76.7 ± 6.9
|
73.9 ± 6.6
|
<0.001
|
85.8 ± 5.6
|
83.1 ± 7.3
|
0.001
|
Male, n (%)
|
112 (62.1)
|
2847 (57.5)
|
0.001
|
56(72.7)
|
649(63.8)
|
0.138
|
Comorbid conditions, n (%)
|
|
|
|
|
|
|
Smoking
|
67 (42.1)
|
2618 (52.9)
|
0.012
|
25(32.5)
|
372(36.5)
|
0.617
|
Preexisting coronary artery disease
|
67 (42.1)
|
877 (17.7)
|
<0.001
|
23(29.9)
|
258(25.3)
|
0.417
|
COPD
|
26 (16.4)
|
667 (13.5)
|
0.906
|
15(19.5)
|
228(22.4)
|
0.866
|
Lung cancer
|
16 (10.1)
|
463 (9.3)
|
0.782
|
7(9.1)
|
102(10.0)
|
0.812
|
Diabetes
|
65(40.9)
|
1031(20.8)
|
<0.001
|
35(45.5)
|
334(32.8)
|
0.033
|
Hypertension
|
99 (62.3)
|
2409 (48.6)
|
0.001
|
23(29.9)
|
347(34.1)
|
0.523
|
Hypercholesterolemia
|
29 (18.2)
|
432 (8.7)
|
<0.001
|
62(80.5)
|
873(85.8)
|
0.239
|
Chronic heart failure
|
6 (3.8)
|
40 (0.8)
|
0.003
|
27(35.1)
|
355(34.8)
|
0.936
|
Cerebrovascular disease
|
22 (13.8)
|
327 (6.6)
|
0.001
|
16(20.8)
|
187(18.4)
|
0.648
|
Chronic renal failure
|
6 (3.8)
|
85 (1.7)
|
0.063
|
10(12.9)
|
69(6.8)
|
0.062
|
Chronic liver disease
|
6 (3.8)
|
145 (2.9)
|
0.474
|
5(6.5)
|
37(3.6)
|
0.211
|
Clinical symptoms of chief complaint on admission, n (%)
|
Fever
|
95 (59.7)
|
3170 (64.0)
|
0.276
|
11(14.3)
|
321(31.5)
|
0.001
|
Cough and expectoration
|
79 (49.7)
|
2362 (47.7)
|
0.629
|
24(31.2)
|
395(38.8)
|
0.224
|
Chest pain
|
13 (8.2)
|
222 (4.5)
|
0.030
|
9(11.7)
|
38(3.8)
|
0.004
|
Dyspnea
|
42(26.4)
|
693 (13.9)
|
<0.001
|
64(83.1)
|
884(86.8)
|
0.384
|
Duration of symptoms
|
6.9 ± 6.7
|
7.17 ± 7.0
|
0.927
|
5.6 ± 4.9
|
5.1 ± 7.0
|
0.716
|
Clinical data, n (%)
|
|
|
|
|
|
|
NIV/IMV
|
17 (10.7)
|
155 (3.1)
|
<0.001
|
7(9.1)
|
16(1.6)
|
0.001
|
Respiratory failure
|
41(25.8)
|
776(15.7)
|
0.001
|
28(36.3)
|
253(24.9)
|
0.021
|
Impaired consciousness
|
3 (1.9)
|
40 (0.8)
|
0.150
|
13(16.9)
|
46(4.5)
|
<0.001
|
Respiratory rate ≥ 30/min
|
4(2.5)
|
55(1.1)
|
0.110
|
2(2.6)
|
13(1.3)
|
0.028
|
SBP < 90 mmHg or DBP ≤ 60 mmHg
|
19(11.9)
|
12(0.2)
|
<0.001
|
10(12.9)
|
133(13.1)
|
0.576
|
T < 36℃ or ≥ 40℃
|
2(1.3)
|
4(0.1)
|
0.003
|
2(2.6)
|
4(0.4)
|
0.061
|
Heart rate ≥ 125 bpm.
|
2(1.3)
|
45(0.9)
|
<0.001
|
5(6.5)
|
17(1.7)
|
0.015
|
BUN ≥ 7 mmol/L
|
95(59.7)
|
1412(28.5)
|
<0.001
|
67(87.0)
|
610(59.9)
|
<0.001
|
WBC < 4.0 × 109/L or ≥ 10.0 × 109/L
|
71(44.7)
|
2319(46.8)
|
0.323
|
26(33.8)
|
72(7.1)
|
<0.001
|
PLT < 10.0 × 109/L
|
14(8.8)
|
7(0.1)
|
<0.001
|
4(5.2)
|
5(0.5)
|
0.002
|
PH < 7.35
|
15(9.4)
|
447(9.0)
|
0.471
|
17(22.1)
|
2(0.2)
|
0.001
|
Serum sodium < 130 mmol/L
|
50(31.4)
|
903(18.2)
|
<0.001
|
29(37.7)
|
274(26.9)
|
0.011
|
HCT < 30%
|
21(13.2)
|
491(9.9)
|
0.112
|
8(10.4)
|
68(6.7)
|
0.157
|
Blood glucose ≥ 14 mmol/L
|
11(6.9)
|
74(1.5)
|
<0.001
|
36(46.8)
|
362(35.6)
|
0.034
|
Pleural effusion
|
122 (76.7)
|
4089 (82.6)
|
0.071
|
20(25.9)
|
194(19.1)
|
0.139
|
Pathogens
|
|
|
|
|
|
|
Bacterial pneumonia
|
126 (79.2)
|
4011 (81.0)
|
0.952
|
61(79.2)
|
845(83.0)
|
0.636
|
Viral pneumonia
|
3 (1.9)
|
64 (1.3)
|
0.465
|
5(6.5)
|
68(6.7)
|
0.570
|
Fungal pneumonia
|
8 (5.0)
|
140 (2.8)
|
0.140
|
7(9.1)
|
113(11.1)
|
0.736
|
Death in hospital, n (%)
|
16 (10.1)
|
118 (2.4)
|
<0.001
|
11(14.3)
|
39(3.8)
|
<0.001
|
Length of stay, days
|
13.8 ± 8.9
|
12.1 ± 9.8
|
0.023
|
13.8 ± 11.5
|
11.2 ± 10.1
|
0.030
|
*For comparisons between AMI group and Without AMI group. Data are presented as mean (standard deviation) or %. AMI: acute myocardial infarction. CAP: community-acquired pneumonia. COPD: chronic obstructive pulmonary disease. IMV: invasive mechanical ventilation. NIV: non-invasive ventilation. SBP: Systolic blood pressure. DBP: Diastolic blood pressure. T: Body temperature. bpm: beats per minute. BUN: blood urea nitrogen. WBC: white blood cell. PLT: blood platelet. PaO2: arterial oxygen tension. SPO2: pulse oxygen saturation. PH: potential of hydrogen. HCT: hematocrit. |
2. Comparison of the characteristics between elderly patients and non-elderly patients who experiencing AMI during CAP hospitalization
In a further analysis, patients ≥ 65 years were compared with those patients <65 years experiencing AMI during CAP hospitalization(Table 2). We identified a total of the 11009 patients who were diagnosed with CAP and age ≥ 18 years was hospitalized in the respiratory ward, consisted of 5111 elderly patients ≥ 65 years and 5898 patients <65 years. 159 patients ≥ 65 years and 61patients <65 years experienced AMI during hospitalization for CAP in respiratory ward. As shown in Fig. 1, AMI after CAP were more frequently seen in elderly patients (3.1% vs. 1.0%).
Table 2
Comparison of clinical characteristics between ≥ 65 years and < 65 years inpatients with CAP experiencing AMI
Characteristic
|
≥ 65 years ,n = 159
|
<65 years,n = 61
|
P value*
|
Age, years
|
76.7 ± 6.9
|
57.8 ± 5.2
|
<0.001
|
Male, n (%)
|
112 (62.1)
|
56(91.8)
|
0.012
|
Comorbid conditions, n (%)
|
|
|
|
Smoking
|
67 (42.1)
|
54(88.5)
|
<0.001
|
Preexisting coronary artery disease
|
67 (42.1)
|
39(63.9)
|
0.768
|
COPD
|
26 (16.4)
|
9(14.8)
|
0.968
|
Lung cancer
|
16 (10.1)
|
3(4.9)
|
0.203
|
Diabetes
|
65(40.9)
|
43(70.5)
|
<0.001
|
Hypertension
|
99 (62.3)
|
29(47.5)
|
0.008
|
Hypercholesterolemia
|
29 (18.2)
|
24(39.3)
|
0.002
|
Chronic heart failure
|
6 (3.8)
|
1(1.6)
|
0.376
|
Cerebrovascular disease
|
22 (13.8)
|
4(6.6)
|
0.115
|
Chronic renal failure
|
6 (3.8)
|
1(1.6)
|
0.376
|
Chronic liver disease
|
6 (3.8)
|
5(8.2)
|
0.300
|
Clinical symptoms of chief complaint on admission, n (%)
|
Fever
|
95 (59.7)
|
46(75.4)
|
0.224
|
Cough and expectoration
|
79 (49.7)
|
40(65.6)
|
0.143
|
Chest pain
|
13 (8.2)
|
12(42.1)
|
0.018
|
Dyspnea
|
42(26.4)
|
9(14.8)
|
0.046
|
Duration of symptoms
|
6.9 ± 6.7
|
5.2 ± 3.8
|
0.589
|
Clinical data, n (%)
|
|
|
|
NIV/IMV
|
17 (10.7)
|
4(6.6)
|
0.255
|
respiratory failure
|
41(25.8)
|
6(9.8)
|
0.001
|
Impaired consciousness
|
3 (1.9)
|
0(0.0)
|
0.376
|
Respiratory rate ≥ 30/min
|
4(2.5)
|
1(1.6)
|
0.575
|
SBP < 90 mmHg or DBP ≤ 60 mmHg
|
19(11.9)
|
7(11.5)
|
0.596
|
T < 36℃ or ≥ 40℃
|
2(1.3)
|
2(3.3)
|
0.308
|
Heart rate ≥ 125 bpm.
|
2(1.3)
|
1(1.6)
|
0.108
|
BUN ≥ 7 mmol/L
|
95(59.7)
|
14(22.9)
|
0.000
|
WBC < 4.0 × 109/L or ≥ 10.0 × 109/L
|
71(44.7)
|
41(67.2)
|
0.002
|
PLT < 10.0 × 109/L
|
14(8.8)
|
5(8.2)
|
0.562
|
PH < 7.35
|
15(9.4)
|
2(3.3)
|
0.106
|
Serum sodium < 130 mmol/L
|
50(31.4)
|
8(13.1)
|
0.005
|
HCT < 30%
|
21(13.2)
|
6(9.8)
|
0.333
|
Blood glucose ≥ 14 mmol/L
|
11(6.9)
|
6(9.8)
|
0.319
|
Pleural effusion
|
122 (76.7)
|
53(86.9)
|
0.482
|
Pathogens
|
|
|
|
Bacterial pneumonia
|
126 (79.2)
|
49 (80.3)
|
0.892
|
Viral pneumonia
|
3 (1.9)
|
2(3.3)
|
0.425
|
Fungal pneumonia
|
8 (5.0)
|
3(4.9)
|
0.638
|
Died during hospital stay, n (%)
|
16 (10.1)
|
4(6.6)
|
0.301
|
Length of stay, days
|
13.8 ± 8.9
|
12.3 ± 7.4
|
0.328
|
*For comparisons between ≥ 65 years group and < 65 years group. Data are presented as mean (standard deviation) or % |
AMI: acute myocardial infarction. CAP: community-acquired pneumonia. COPD: chronic obstructive pulmonary disease. SBP: Systolic blood pressure. DBP: Diastolic blood pressure. T: Body temperature. bpm: beats per minute. BUN: blood urea nitrogen. WBC: white blood cell. PLT: blood platelet. PaO2: arterial oxygen tension. SPO2: pulse oxygen saturation. PH:potential of hydrogen. IMV: invasive mechanical ventilation. NIV: non-invasive ventilation. |
We noted that higher proportion patients suffer from respiratory failure in elderly patients (P = 0.001). More patients ≥ 65 years had hypertension (P = 0.008) and dyspnea (P = 0.046). Moreover, BUN ≥ 7 mmol/L (P < 0.001), serum sodium < 130 mmol/L(P = 0.005) were more frequently present in patients ≥ 65 years. On the other hand, those patients༜65 years had higher percentage of male (P = 0.012), smoking history (P < 0.001), diabetes (P < 0.001), hypercholesterolemia (P = 0.002), chest pain (P = 0.019) and abnormal white blood cell count (P = 0.002). As shown in Fig. 1, patients ≥ 65 years had a higher in-hospital mortality compared to patients <65 years (10.1% vs. 6.6%).
3. Association between incidence of AMI during CAP hospitalization and in-hospital mortality
As shown in Fig. 1, in-hospital mortality was higher among elderly patients hospitalized with CAP in the respiratory ward who developed AMI compared to those who did not (10.1% vs.2.4%). We also investigated the association between incidence of AMI during CAP hospitalization and in-hospital mortality using logistic regression, the occurrence of AMI and Age as the independent variable and patient’s vital status at discharge as the dependent variable.
In logistic regression model (Fig. 2), the development of AMI was associated with a increase in the risk of death during CAP hospitalization, AMI during hospitalization showed an OR for in-hospital mortality of 1.49 (95%CI: 1.24–1.82; P < 0.01). This association remained significant after adjustment for Age (OR, 1.47; 95%CI, 1.32–1.64; P < 0.01) and for respiratory failure (OR, 1.31; 95% CI, 1.25–1.36; P < 0.01). Conversely, we did not identify evidence of an association between in-hospital mortality and MI in people aged < 65 years. similar meaningful statistical results could not be obtained.
4. Risk factors correlated with the occurrence of AMI during hospitalization for pneumonia in the elderly patients
The logistic regression analysis of risk factors for AMI during hospitalization in the elderly patients is shown in Table 3. Input variables for logistic regression analysis were selected from significant variables obtained from the univariate analysis. In 5111 elderly patients ≥ 65 years in the respiratory ward, respiratory failure (OR,1.34; 95% CI,1.15–1.54; p<0.01), preexisting coronary artery disease (OR,1.31; 95% CI,1.07–1.59; p = 0.02), diabetes (OR,1.26; 95% CI,1.11–1.42;p = 0.02), BUN (OR,1.23; 95% CI,1.01–1.49; p = 0.04) were significantly correlated with the occurrence of AMI, as shown in Table 3. In 1095 geriatric patients in geriatrics ward, logistic regression analysis showed that impaired consciousness (OR, 1.19; 95% CI, 1.07–1.32; P = 0.03) and respiratory failure (OR, 1.29; 95% CI, 1.19–1.41; P = 0.01) were independent risk factors for the occurrence of AMI.
Table 3
Logistic regression analyses of risk factors for AMI during hospitalization in geriatric patients with CAP*
Characteristics
|
OR (95% CI)
|
P value
|
Patients in respiratory ward
|
|
|
Respiratory failure
|
1.34(1.15–1.54)
|
<0.01
|
Preexisting coronary artery disease
|
1.31(1.07–1.59)
|
0.02
|
Diabetes
|
1.26(1.11–1.42)
|
0.02
|
BUN
|
1.23(1.01–1.49)
|
0.04
|
Patients in geriatrics ward
|
|
|
Respiratory failure
|
1.29(1.19–1.41)
|
0.01
|
Impaired consciousness
|
1.19(1.07–1.32)
|
0.03
|
*Variables in the logistic regression that did not have a significant independent association with AMI in both model were: Age, Male, Hypertension, Hypercholesterolemia, SBP, WBC, Serum sodium.
OR: odds ratio. Cl: confidence interval. AMI: acute myocardial infarction. CAP: community-acquired pneumonia. BUN: blood urea nitrogen. SBP: Systolic blood pressure. WBC: white blood cell. HCT: hematocrit.
|