Ann Thorac Surg 2010;89:490-495. doi:10.1016/j.athoracsur.2009.09.073
© 2010 The Society of Thoracic Surgeons
Original Articles: Adult Cardiac
Survival and Quality of Life in Cardiac Surgery Patients With Prolonged Intensive Care
Emma Lagercrantz, MDa,
Dan Lindblom, MD, PhDa,b,
Ulrik Sartipy, MD, PhDa,b,*
a Department of Cardiothoracic Surgery and Anesthesiology, Karolinska University Hospital, Stockholm, Sweden
b Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
Accepted for publication September 29, 2009.
* Address correspondence to Dr Sartipy, Department of Cardiothoracic Surgery and Anesthesiology, Karolinska University Hospital, Stockholm, SE-171 76, Sweden (Email: ulrik.sartipy{at}karolinska.se).
 |
Abstract
|
|---|
Background: The clinical outcome in discharged cardiac surgery patients after prolonged postoperative intensive care needs further investigation. The aim was to study survival, functional status, and quality of life in cardiac surgery patients with more than 10 days postoperative intensive care unit stay.
Methods: We performed a population-based study including 4,086 cardiac surgery patients and identified 141 patients who had a postoperative intensive care unit stay of more than 10 days. Data regarding patients and outcome were collected, and all discharged patients alive in May 2008, or a family member, were contacted to assemble information regarding functional status and quality of life using the Karnofsky performance scale and the Short Form-36 questionnaire.
Results: Early mortality was 33%. Risk factors for early mortality were advanced age and postoperative dialysis. Survival at 1, 3, and 5 years was 62%, 56%, and 52%, respectively. Ninety-five patients were discharged from the hospital, and during a mean follow-up of 1.9 years, 62% were readmitted at least once. In discharged patients, 65% had a Karnofsky score of 80 or more. We found significantly lower physical (39.7 versus 43.6; p = 0.03), and mental (44.1 versus 50.8; p = 0.001) scores in the study group compared with a reference group.
Conclusions: Early mortality was high, especially in patients who required dialysis. However, long-term survival and functional status were encouraging. Quality of life was worse compared with the general population in both physical and mental aspects, but the difference was moderate. Extensive efforts in this patient group seem reasonable despite high resource utilization.
|
Introduction
|
|---|
The literature provides conflicting information regarding prognosis, survival, functional status, and quality of life after prolonged intensive care unit (ICU) stay after cardiac surgery [1–7]. Currently, 4% to 11% of all cardiac surgery patients at a tertiary referral center require prolonged postoperative intensive care [1–3, 6–9]. The mortality in this patient group is high during the hospital stay. Prolonged intensive care is extremely demanding regarding health-care resource consumption, and the benefit has been questioned both for economic and ethical reasons. To make accurate decisions concerning further therapeutic strategies and allocation of resources and medical priorities, a better understanding about prognosis, survival, and quality of life in spite of prolonged intensive care after cardiac surgery is needed.
We performed a retrospective population-based cohort study. The primary objective was to study survival, functional status, and quality of life in cardiac surgery patients with more than 10 days of postoperative ICU stay. A secondary objective was to identify factors associated with poor survival.
|
Patients and Methods
|
|---|
The study was approved by the regional Human Research Ethics Committee, Stockholm, Sweden (Dnr: 2008/41–31/2). Informed consent was obtained from all patients participating in the follow-up of functional status and quality of life. For the remaining patients, informed consent was waived.
Setting and Study Population
Using institutional registries, we identified 4,086 patients who underwent cardiac surgery at Karolinska University Hospital between January 1, 2004, and December 31, 2007. During this period, except for the first 6 months, our institution was the only provider of cardiothoracic surgery in Stockholm County, the most densely populated area in Sweden, serving more than 2 million inhabitants, making this a population-based cohort study. Patients who underwent surgery on the descending aorta, heart transplant, or mechanical assist device or extracorporeal membrane oxygenation as the only intervention were excluded. We used the departmental administrative records to identify patients with more than 10 days of postoperative stay in the cardiac surgery ICU. Patients who were transferred from the cardiac surgery ICU to a general ICU at our or another hospital were identified using the same registry, and the patient charts were used to confirm a total postoperative ICU stay exceeding 10 days. By this procedure, all patients with a postoperative ICU stay of more than 10 days after cardiac surgery were identified, and they constitute the study population. Patient characteristics and operative and postoperative details were extracted from institutional registries and patient charts. The European System for Cardiac Operative Risk Evaluation (EuroSCORE) was calculated for each patient [10]. The logistic EuroSCORE produces a more accurate risk prediction in high-risk patients compared with the additive score [11]. For completeness, we report both logistic and additive EuroSCORE.
Outcome Measures
Early mortality was defined as death within 30 days from surgery or before hospital discharge. Survival was ascertained in July 2009 by use of the Swedish personal identity number and the continuously updated national total population registry. Cause of death was obtained from patient charts. Patients who were discharged from the hospital were contacted by telephone. Functional status was estimated according to Karnofsky performance status [12] by interview with the patient or a family member if the patient had died after hospital discharge. The family member was asked to report the best score achieved by the patient after hospital discharge. The Karnofsky performance status scale is shown in Table 1. The Medical Outcome Study 36-Item Short Form (SF-36) questionnaire [13] was sent to all patients who were alive at follow-up. Patients were asked to fill out the form and return it by mail in the enclosed self-addressed stamped envelope. A reminder was sent out after 1 month to those patients who had not returned the questionnaire. The SF-36 (Swedish version) is a standardized, self-administered survey measuring health-related quality of life [13, 14]. The subscales and summary scores can be compared with the general population allowing norm-based interpretation. In all scales, higher score indicates better health. Several advantages of the physical component summary and mental component summary scores over the original eight scales of the SF-36 have been reported [13, 15]; however, the summary scores should always be interpreted in combination with the subscale scores [16].
Statistical Analyses
Continuous variables are presented as means and one standard deviation, and categorical data are summarized as frequencies and percentages. Wilcoxon signed-rank test was used to compare SF-36 scale scores between the study group and the reference group. The Mann-Whitney U test was used for comparisons of outcomes between groups readmitted to the hospital or not. Cumulative survival was estimated by the Kaplan-Meier method. Logistic regression analysis was used to analyze associations between preoperative, perioperative, and postoperative variables and early mortality. A two-tailed probability value of 0.05 was used to indicate statistical significance. Statistical analyses were performed using SPSS 15.0 (SPSS, Chicago, IL).
|
Results
|
|---|
During the period from January 2004 to December 2007, 4,086 patients underwent cardiac surgery at Karolinska University Hospital. Among these, we identified 141 (3.5%) who required a postoperative ICU stay of more than 10 days. The mean age was 68 years, and 24% were women. The mean additive EuroSCORE was 7.8, and the mean logistic EuroSCORE was 13. Sixteen patients (11%) had previously undergone cardiac surgery. An elective procedure was performed in 44%, and 38% underwent an urgent procedure. In 18%, an emergent operation was performed. Preoperative patient characteristics are shown in Table 2. All patients underwent surgery using cardiopulmonary bypass. Postoperative renal failure requiring dialysis affected 46% of the patients. A postoperative stroke occurred in 15%. An early reoperation was necessary in 43% of the patients, mostly because of bleeding. A percutaneous tracheostomy was performed in 32%. Operative and postoperative details are shown in Tables 3 and 4.
The mean stay in the cardiac surgery ICU was 16 days for all patients (n = 141) and 15 days for patients who eventually could be discharged home (n = 95). The mean total hospital stay in patients who were finally discharged home was 68 days.
Survival
Early mortality was 33%. Causes of death were predominantly cardiac failure and multiple organ failure. There was a strong and significant association between postoperative dialysis and early mortality (odds ratio, 3.7; 95% confidence interval, 1.8 to 7.8; p = 0.001). The risk remained unchanged after adjustments for age, sex, preoperative creatinine level, cardiopulmonary bypass time, and EuroSCORE. Causes of death are listed in Table 5. Survival at 1 year was 62%, 56% at 3 years, and 52% at 5 years, and is shown in Figure 1. Causes of death in the late phase are shown in Table 5. The cumulative follow-up time was 277 patient-years, and the mean follow-up in all patients, excluding early mortality, was 2.9 years. In patients who were discharged from the hospital (n = 95), survival at 1 year was 92%, and at 3 years, 83%.
View larger version (13K):
[in this window]
[in a new window]
|
Fig 1. Overall survival in 141 patients with more than 10 days of intensive care unit stay after cardiac surgery.
|
|
Hospital Readmissions During Follow-Up
In patients who were discharged from the hospital (n = 95), 38% were never readmitted, 37% were readmitted once or twice, and 25% were readmitted three times or more during a mean follow-up time of 1.9 years.
Quality of Life and Functional Status
Data on functional status according to Karnofsky performance score were obtained in 68 of 95 patients (72%) who were discharged. The mean follow-up regarding functional status was 1.9 years. The mean Karnofsky score was 79, and 65% of the patients had a Karnofsky score of 80 or more, indicating a capacity to perform normal activities without need for assistance. A Karnofsky score of 50 or less, demonstrating a situation in which considerable assistance is required, was reported by 13%. The Karnofsky score distribution is shown in Figure 2. The SF-36 questionnaire was returned by 60 of 82 patients who were alive in May 2008. Thus, the response rate regarding quality of life was 73%. The subscale and the summary scores of the study population were compared with scores from an age- and sex-matched reference group from the general Swedish population. The reference data are provided in the SF-36 manual [13]. The study group had significantly lower scores in all subscales, except for bodily pain. There were significantly lower physical (39.7 versus 43.6; p = 0.03) and mental (44.1 versus 50.8; p = 0.001) component summary scores in the study group compared with the reference group. The SF-36 scores in the study group and the reference group are shown in Table 6
and Figure 3. As expected, the mean Karnofsky score (76 versus 85; p = 0.07) and both physical (36 versus 44; p = 0.03) and mental (41 versus 48; p = 0.13) component summary scores demonstrated a tendency to be worse in patients with one or more readmissions compared with patients not readmitted to the hospital during follow-up.
View larger version (16K):
[in this window]
[in a new window]
|
Fig 2. Functional status estimated by the Karnofsky performance score in 68 discharged patients with more than 10 days of intensive care unit stay after cardiac surgery after a mean follow-up of 1.9 years. The mean Karnofsky score was 79. In 65% of the patients the Karnofsky score was 80 or above, representing a capacity to perform normal activities without need for assistance.
|
|
View this table:
[in this window]
[in a new window]
|
Table 6 Short Form-36 Scores in 60 Patients Surviving Prolonged Intensive Care After Cardiac Surgery Compared With an Age- and Sex-Matched Reference Population
a
|
|
View larger version (28K):
[in this window]
[in a new window]
|
Fig 3. Health-related quality of life according to Short Form-36 subscale scores in 60 discharged patients with more than 10 days of intensive care unit stay after cardiac surgery compared with an age- and sex-matched reference population 1.9 years after surgery. (BP = bodily pain; GH = general health; MH = mental health; PF = physical functioning; RE = emotional role functioning; RP = physical role functioning; SF = social functioning; VT = vitality.)
|
|
|
Comment
|
|---|
One third of all patients with a postoperative ICU stay longer than 10 days died within 30 days or before hospital discharge. Survival at 1 and 5 years was 62% and 52%, respectively. In patients who could be discharged alive, two thirds had a close to normal functional capacity, but both physical and mental aspects of health-related quality of life were lower compared with an age- and sex-matched reference group from the general population. Sixty-two percent were readmitted at least once, and there was a tendency toward lower functional status and quality of life in this group compared with patients without need for hospital readmission.
The incidence of prolonged ICU stay after cardiac surgery diverge in the literature from 4% to 11%, basically depending on the definition of prolonged ICU stay [1–3, 6–9]. We decided to include patients with an ICU stay of more than 10 days, as previously reported by others [2, 3].
Early mortality was high in the study group, especially in patients requiring dialysis. The need for renal replacement therapy among patients with more than 10 days postoperative ICU stay after cardiac surgery was strongly and significantly associated with early mortality. The association between dialysis and early mortality among patients with prolonged ICU stay after cardiac surgery has previously been demonstrated [8]. The EuroSCORE is a validated and widely used predictive risk model assessing early mortality in cardiac surgery [10], and has also been shown to predict prolonged ICU stay after cardiac surgery [17]. In our study, the EuroSCORE was not significantly associated with early mortality. However, our study group consisted only of patients who had survived the first 10 days and were therefore not representative of the total cardiac surgery population.
Several studies have investigated the long-term results concerning survival and quality of life after prolonged ICU stay after cardiac surgery, and they have to some extent reached different conclusions. Attempts to compare results from previously published studies are hampered by the multiplicity of inclusion criteria and outcome measures.
A Swedish study [5] included 225 patients who underwent primary heart valve operations and who required at least 8 days in the ICU after surgery. They reported an early mortality of 12% and 5-year survival of 68%, compared with 33% and 52% in our study. With a response rate of 87%, they found an impaired quality of life in terms of physical health but equal mental health when compared with matched control patients who had an uncomplicated ICU stay. Mazzoni and colleagues [6] in Italy studied 115 consecutive cardiac surgical patients who had an ICU stay exceeding 4 days. Early mortality was 10%. They found that EuroSCORE was associated with the combined endpoint of all-cause death or cardiovascular admission. Another study from Italy included 57 cardiac surgery patients with more than 10 days of postoperative ICU stay and who were discharged alive from the hospital [3]. During the study period, 121 of 3,125 patients had a postoperative ICU stay longer than 10 days, and 64 patients died in the hospital, and thus early mortality was 53%. Among the surviving 57 patients, 45 died during the 7-year follow-up period. Most patients had a Karnofsky score less than 50, and there was no tendency toward improvement with time. The authors concluded that mortality among patients with prolonged ICU stay, who were eventually discharged alive, was very high, and the quality of life in surviving patients was low. Williams and coworkers [7] identified 49 patients with a postoperative ICU stay of more than 14 days. These patients represented less than 4% of their total patient population, but they consumed one third of all ICU bed days for 1 year, and the hospital mortality was 28.5%. On the other hand, in patients who survived to hospital discharge, 63% were alive at 2 years, and 86% had a normal quality of life. A study from the Cleveland Clinic included 142 patients with an initial ICU length of stay of 10 or more consecutive days [2]. Hospital mortality was 33%. They found that not every patient who was successfully discharged from the hospital had a good outcome in terms of survival and functional capacity. The authors concluded that hospital discharge was an imperfect measure of outcome, and they advocated long-term follow-up for understanding treatment benefit in patients with prolonged ICU stay.
Limitations of the Study
Owing to the nonprospective study design, follow-up time for assessment of functional status and quality of life varied between patients. However, the mean follow-up time was almost 2 years, which can be considered sufficient. Another drawback is the lack of preoperative data on quality of life and functional status. An impaired preoperative quality of life has been shown to be a strong predictor of impaired quality of life late after coronary surgery [18]. Although this study analyzed a single-institution experience, which has implications on the generalizability of the results, the study is also population based, partly compensating for this deficiency in study design. The response rate regarding functional status and quality of life was 72% and 73%, respectively, and is generally considered acceptable. However, it is entirely possible that nonresponders were different from responders, which may have introduced bias. We found that 62% of discharged patients were readmitted to the hospital at least once after the index hospitalization. The study lacks information regarding reasons for readmissions after hospital discharge. The patients in the study group had other concomitant conditions in addition to cardiac disease, and more detailed information could provide a better understanding in this area inasmuch as it is conceivable that repeated hospitalization has consequences on perceived quality of life. We included patients during a very recent and fairly short period to minimize bias arising from changes in ICU practices that occur during time. During the study inclusion period, the institutional policies for initiating various procedures such as starting dialysis or performing percutaneous tracheostomy were practically unchanged.
Conclusions
Early mortality in patients with a postoperative ICU stay longer than 10 days was high, especially in patients who required dialysis. Long-term survival and functional status were encouraging. Quality of life was worse compared with that of the general population in both physical and mental aspects, but the difference was only of moderate magnitude. Extensive efforts in this patient group seem reasonable despite high resource utilization.
|
References
|
|---|
- Bapat V, Allen D, Young C, Roxburgh J, Ibrahim M. Survival and quality of life after cardiac surgery complicated by prolonged intensive care J Card Surg 2005;20:212-217.[Medline]
- Bashour CA, Yared JP, Ryan TA, et al. Long-term survival and functional capacity in cardiac surgery patients after prolonged intensive care Crit Care Med 2000;28:3847-3853.[Medline]
- Gaudino M, Girola F, Piscitelli M, et al. Long-term survival and quality of life of patients with prolonged postoperative intensive care unit stay: unmasking an apparent success J Thorac Cardiovasc Surg 2007;134:465-469.[Abstract/Free Full Text]
- Hein OV, Birnbaum J, Wernecke K, England M, Konertz W, Spies C. Prolonged intensive care unit stay in cardiac surgery: risk factors and long-term-survival Ann Thorac Surg 2006;81:880-885.[Abstract/Free Full Text]
- Hellgren L, Ståhle E. Quality of life after heart valve surgery with prolonged intensive care Ann Thorac Surg 2005;80:1693-1698.[Abstract/Free Full Text]
- Mazzoni M, De Maria R, Bortone F, et al. Long-term outcome of survivors of prolonged intensive care treatment after cardiac surgery Ann Thorac Surg 2006;82:2080-2087.[Abstract/Free Full Text]
- Williams MR, Wellner RB, Hartnett EA, et al. Long-term survival and quality of life in cardiac surgical patients with prolonged intensive care unit length of stay Ann Thorac Surg 2002;73:1472-1478.[Abstract/Free Full Text]
- Gersbach P, Tevaearai H, Revelly JP, Bize P, Chiolero R, von Segesser LK. Are there accurate predictors of long-term vital and functional outcomes in cardiac surgical patients requiring prolonged intensive care? Eur J Cardiothorac Surg 2006;29:466-472.[Free Full Text]
- Isgro F, Skuras JA, Kiessling AH, Lehmann A, Saggau W. Survival and quality of life after a long-term intensive care stay Thorac Cardiovasc Surg 2002;50:95-99.[Medline]
- Nashef SA, Roques F, Michel P, Gauducheau E, Lemeshow S, Salamon R. European system for cardiac operative risk evaluation (EuroSCORE) Eur J Cardiothorac Surg 1999;16:9-13.[Abstract/Free Full Text]
- Michel P, Roques F, Nashef SA. Logistic or additive EuroSCORE for high-risk patients? Eur J Cardiothorac Surg 2003;23:684-687.[Abstract/Free Full Text]
- Karnofsky DA, Burchenal JH. The clinical evaluation of chemotherapeutic agents in cancerIn: MacLeod CM, editor. Evaluation of chemotherapeutic agents. New York: Columbia University Press; 1949. pp. 199-205.
- Sullivan M, Karlsson J, Taft C. SF-36 Hälsoenkät: Swedish manual and interpretation guide2nd ed.. Gothenburg: Sahlgrenska University Hospital; 2002.
- Sullivan M, Karlsson J, Ware Jr JE. The Swedish SF-36 Health Survey—I. Evaluation of data quality, scaling assumptions, reliability and construct validity across general populations in Sweden. Soc Sci Med 1995;41:1349-1358.[Medline]
- Ware Jr JE, Gandek B, Kosinski M, et al. The equivalence of SF-36 summary health scores estimated using standard and country-specific algorithms in 10 countries: results from the IQOLA Project. International Quality of Life Assessment. J Clin Epidemiol 1998;51:1167-1170.[Medline]
- Taft C, Karlsson J, Sullivan M. Do SF-36 summary component scores accurately summarize subscale scores? Qual Life Res 2001;10:395-404.[Medline]
- Messaoudi N, De Cocker J, Stockman BA, Bossaert LL, Rodrigus IE. Is EuroSCORE useful in the prediction of extended intensive care unit stay after cardiac surgery? Eur J Cardiothorac Surg 2009;36:35-39.[Abstract/Free Full Text]
- Herlitz J, Brandrup-Wognsen G, Caidahl K, et al. Determinants for an impaired quality of life 10 years after coronary artery bypass surgery Int J Cardiol 2005;98:447-452.[Medline]
Related Article
-
Invited Commentary
- Jessica Hathaway and Andrew Shaw
Ann. Thorac. Surg. 2010 89: 495-496.
[Extract]
[Full Text]
[PDF]
This article has been cited by other articles:
|
|
|
|
 
A. Hassan, C. Anderson, A. Kypson, L. Kindell, T. B. Ferguson, W. R. Chitwood Jr, and E. Rodriguez
Clinical Outcomes in Patients With Prolonged Intensive Care Unit Length of Stay After Cardiac Surgical Procedures
Ann. Thorac. Surg.,
February 1, 2012;
93(2):
565 - 569.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. P. Dobson
Membrane polarity: A target for myocardial protection and reduced inflammation in adult and pediatric cardiothoracic surgery
J. Thorac. Cardiovasc. Surg.,
December 1, 2010;
140(6):
1213 - 1217.
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. Hathaway and A. Shaw
Invited Commentary
Ann. Thorac. Surg.,
February 1, 2010;
89(2):
495 - 496.
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
