We identified a total of 1,412,985 patients from January 2007 to December 2017 who suffered in-hospital SCA after excluding for age ≤ 18 years, AKI and prior history of renal transplantation. Out of these patients, about 123,962 (9.6%) patients had ESRD (please see Fig. 1). Baseline characteristics of the study population are shown in Table 1. ESRD patients who suffered in-hospital SCA were younger when compared to non-ESRD patients with in-hospital SCA in unadjusted analysis (65 years vs. 69 years, p < 0.01). Female patients were equally represented in both groups (44.7% vs. 44.7%, p = 0.45). ESRD was less prevalent in White patients (40.1% vs. 66.1%, p < 0.01) and more prevalent in Blacks (36.7% vs. 18.6%, p < 0.01) and Hispanics (15% vs. 9.1%, p < 0.01) in unadjusted analysis. In terms of co-morbidity burden, congestive heart failure (34.8% vs. 21.8%, p < 0.01), complicated diabetes (32.5% vs. 8.4%, p < 0.01), hypertension (80.9% vs. 50.4%, p < 0.01), coronary artery disease (39.4% vs. 30.8%, p < 0.01) and peripheral vascular disease (19.9% vs. 9.9%, p < 0.01) were more prevalent in ESRD patients who sustained in-hospital SCA when compared to non-ESRD patients. After propensity matching, ESRD patients who suffered in-hospital SCA were younger as compared to non-ESRD patients (65 years vs. 71 years, p < 0.01) and had higher prevalence of anemia (47.6% vs. 46.5%, p = 0.02) and complicated diabetes (32.9% vs. 31.5%, p < 0.01).
Crude and propensity matched outcomes are shown in Table 2. A total of 1,035,037 (73.2%) patients died in our cohort after sustaining an in-hospital SCA. No difference in mortality was noted in PS matched analysis among ESRD and non-ESRD patients with in-hospital SCA (70.4% vs. 70.7%, p = 0.45). The prevalence of new defibrillator (ICD) implantation at discharge continued to be low in ESRD patients who survived an in-hospital SCA compared to non-ESRD patients in both crude and propensity matched cohorts (3.1% vs. 4.8%, p < 0.01 and 3.3% vs. 3.8%. p < 0.01, respectively). The median LOS was 7 days (range 2–15) among ESRD patients who survived in-hospital SCA when compared to 6 days (range 2–13) in non-ESRD patients. Overall cost of hospitalization was 80,150.5$ (range 35,009$-177,894$) in ESRD patients with in-hospital SCA when compared to 65,297$ (range 28,195$-145,639$) in non-ESRD patients. The utilization of invasive cardiovascular procedures such as diagnostic coronary angiogram (7.8% vs. 10.6%, p < 0.01), percutaneous coronary intervention (2.6% vs. 4.6%, p < 0.01) and intra-aortic balloon pump implantation (1.7% vs. 3.4%, p < 0.01) were lower in ESRD patients when compared to non-ESRD patients.
Table 2
Unadjusted and propensity score matched outcomes of the study population
| Unadjusted outcomes | Outcomes after 1:1 propensity score matching |
Variables, No. (%) | Patients without ESRD (n = 1289023) | Patients with ESRD (n = 123962) | P value | Patients without ESRD (n = 22352) | Patients with ESRD (n = 22356) | P value |
Died | 947669(73.6) | 87368(70.5) | P < 0.01 | 15805(70.7) | 15734(70.4) | 0.45 |
Discharge disposition of surviving patients |
Home | 101718(29.9) | 9315(25.5) | P < 0.01 | 1612(24.6) | 1674(25.3) | < 0.01 |
Short term Rehab/Transfer | 46679(13.7) | 3763(10.3) | 702(10.7) | 675(10.2) |
Skilled Nursing facility | 140324(41.2) | 17635(48.2) | 3154(48.2) | 3218(48.6) |
Home with home health | 47884(14.1) | 5205(14.2) | 1004(15.3) | 939(14.2) |
Against medical advice | 2684(0.8) | 445(1.2) | 36(0.5) | 84(1.3) |
Resource Utilization and procedures |
Median cost, $ | 49483(21490–114369) | 76932(33423–171457) | < 0.01 | 65297(28195–145639) | 80150.5(35009–177894) | < 0.01 |
Median length of stay, days | 4(1–10) | 7(2–15) | < 0.01 | 6(2–13) | 7(2–15) | < 0.01 |
New implantable defibrillator at discharge | 16375(4.8) | 1133(3.1) | < 0.01 | 250(3.8) | 223(3.3) | < 0.01 |
Therapeutic temperature management | 13719(1.1) | 1378(1.1) | 0.56 | 262(1.2) | 258(1.2) | 0.58 |
Cardiac catheterization (diagnostic) | 92838(7.3) | 42617(30.2) | < 0.01 | 2365(10.6) | 1741(7.8) | < 0.01 |
Percutaneous coronary intervention | 59958(4.7) | 3107(2.5) | < 0.01 | 1030(4.6) | 581(2.6) | < 0.01 |
Non-ST segment elevation myocardial infarction | 129468(10.0) | 15875(12.8) | < 0.01 | 2770(12.4) | 2924(13.1) | < 0.01 |
ST-segment elevation myocardial infarction | 142751(11.1) | 7131(5.8) | < 0.01 | 2107(9.4) | 1283(5.7) | < 0.01 |
Ventilator support | 833235(64.6) | 87962(71.0) | < 0.01 | 15006(67.1) | 15920(71.2) | < 0.01 |
Utilization of feeding tube | 48885(3.8) | 5594(4.5) | < 0.01 | 1142(5.1) | 1033(4.6) | 0.02 |
Utilization of tracheostomy | 142751(11.1) | 7131(5.8) | < 0.01 | 859(3.8) | 841(3.8) | 0.65 |
Utilization of intra-aortic balloon pump | 15960(1.3) | 31154(22.1) | < 0.01 | 761(3.4) | 378(1.7) | < 0.01 |
Utilization of percutaneous left ventricular assist device | 1102(0.1) | 3937(2.8) | < 0.01 | 91(0.4) | 68(0.3) | 0.07 |
Utilization of vasopressor support | 89364(6.9) | 11310(9.1) | < 0.01 | 1769(7.9) | 2122(9.5) | < 0.01 |
Course complicated by cardiogenic shock | 129300(10.0) | 11815(9.5) | < 0.01 | 2418(10.8) | 2184(9.8) | < 0.01 |
Course complicated by septic shock | 181223(14.1) | 29786(24.0) | < 0.01 | 3692(16.5) | 5451(24.4) | < 0.01 |
ESRD stands for end-stage renal disease |
Over our study period from 2007–2017, the proportion of ESRD and non-ESRD patients who sustained in-hospital SCA was similar (please see Fig. 2). In-patient mortality showed a downward trend for both ESRD and non-ESRD patients with in-hospital SCA after an initial spike in year 2009 (please see Fig. 3). Median LOS showed a stable trend over our study years (please see Fig. 4).
Predictors of mortality in ESRD patients after they sustained SCA are shown in Fig. 5. Advanced age (OR 1.02 per year increase, 95% CI 1.019–1.022), Black race (OR 1.135, 95% CI 1.101–1.171), chronic pulmonary disease (OR 1.056, 95% CI 1.023–1.091), coagulopathy (OR 1.131, 95% CI 1.094–1.169), chronic liver disease (OR 1.325, 95% CI 1.255–1.399) and peripheral vascular disease (OR 1.058, 95% CI 1.02
4-1.094) were independently associated with increased mortality in ESRD patients after a SCA event. Female gender (OR 0.892, 95% CI 0.868–0.916) and prior ICD implantation (OR 0.675, 95% CI 0.624–0.73) were independently associated with reduced mortality in ESRD patients after an in-hospital SCA event.