THE American Heart Association estimated the 2004 prevalence of cardiovascular disease to be 79.4 million persons, 37% of all Americans, with an expected 871 000 deaths to follow.1 Thirty-seven million patients with cardiovascular disease are 65 years or older. Advancing medical technologies have resulted in increasingly longer life spans for patients previously thought to be near death. Postintervention assessments, specifically health-related quality of life (HRQL), are being used to benchmark discussions about institutional resources, patient disposition, and patient satisfaction. Increasing numbers of hospitalized patients are participating in HRQL programs. When all is combined, with increasing numbers of elderly patients having open-heart surgery, a large observable cohort of potential study subjects emerges. In this report, we document the association between survival and HRQL at 1 year among patients who had open-heart surgery.
METHODS
Participants
Subjects were from a single, large, 833-bed regional medical center with Magnet status serving the Northern Virginia - Washington, DC, metropolitan area participating in a prospective cohort study. The study was designed to assess postsurgery functional status changes from baseline to 1 year among elective cardiac surgery patients at our institution. The study was approved by our institutional review board.
All elective surgery patients were required to be admitted for surgery through our Same Day Admission clinic and thus were eligible to participate. A study coordinator approached patients prior to their surgery. Patients were asked to complete a paper questionnaire (SF-20) at the time of their clinic visit and then were mailed a follow-up SF-20 questionnaire at 1 year postsurgery. The HRQL scores at baseline and 1 year postsurgery were reviewed and compared.
Measurements
Patient functional health status was assessed by the Medical Outcomes Trust SF-20 Questionnaire, a standardized, validated questionnaire.2 The SF-20 measures 6 domains of functional health: Physical = limitation in physical activities; Role = limitation in daily activities such as housework, work, or school; Social = extent in which health interferes with routine social activities; Mental Health = general mood or affect in the past month; Health Perception = overall current health in general; Pain = bodily pain in the past month; and Overall = an average of all 6 domain scores. Scales are measured as continuous variables from 0 (worst) to 100 (best). Patients completed the questionnaire preoperatively and at 6 months and 1 year following surgery. Dichotomized variables "Negative Mental Change" (decrease in Mental, Social, or Role domains at 12 months) and "Negative Physical Change" (decrease in Physical, Pain, or Health domains at 12 months) were created to assess global changes in attitude.
Postoperative complications were defined in accordance with the Society of Thoracic Surgeons National Cardiac Database Registry.3 Mediastinitis is deep sternal wound infection. Cerebrovascular accident (CVA) is a permanent neurological deficit persisting for more than 72 hours. Acute renal failure is a postoperative serum creatinine level more than 2.0 mg/dL or twice the preoperative serum creatinine level, or the patient requires new postoperative dialysis.
Mortality data
The ascertainment and date of subsequent death were collected using the Social Security Death Index. The Social Security Death Index is the formal computerized index of death record information for recipients of a US Social Security Number. Survival time from the date of surgery was right censored on August 1, 2006.
Statistical analysis
Continuous data are presented as mean +/- standard deviation. Categorical data are presented as frequency and percentage. Univariate comparisons of preoperative risk factors, demographics, and operative characteristics were performed using the Student t test or chi-square analysis, where appropriate. An analysis of covariance (ANCOVA) was used to predict HRQL scores at 1 year after adjustment for baseline covariates such as baseline HRQL, age, gender, and other potential confounders. Post hoc tests were done via contrasts. Survival estimates at 2, 3, and 5 years following surgery were calculated by the life-table method. Survival curves were compared using the log-rank test. Proportional hazards models were used to generate hazard ratios (HR) and 95% confidence intervals (CI) by comparing mortality estimates between patients with positive and negative HRQL trajectories after controlling for the effects of perioperative complications. Statistical significance was assumed for P <= .05. All analyses were conducted with SAS, Inc (Version 9.2, Cary, North Carolina).
RESULTS
Eight-hundred thirty-six patients completed the preoperative and 1-year postoperative questionnaire (SF-20) out of 1916 patients who responded at baseline: 133 patients underwent a valve procedure, 620 had coronary artery bypass grafting (CABG), 67 patients had CABG plus valve procedure, 15 patients underwent CABG plus other cardiac procedure, and 1 patient had closure of an ASD. Thirty-one operative deaths of 2007 baseline participants (1.5%) were observed. Of the remaining 1976 baseline participants, 57 died within the first year, leaving 1919 available for 1-year follow-up, and 836 (44%) responded and were available for analysis.
Demographics and clinical characteristics of both participants and nonparticipants are presented in Table 1. Participants were 83% male and with an average age of 63 years. The average number of complications per patient was 0.29. Seventy-seven percent of all patients experienced no perioperative complications; 23% experienced 1 or more complications. Average length of stay was 5.8 +/- 7.3 days with atrial fibrillation (16.7%), and acute renal failure was the most common perioperative complication (2.2%).
Patients reported improved HRQL in all domains (Fig 1). The largest absolute gain was documented in the Health domain with an average positive change of 19.5 +/- 24.2. The least gains were shown in the Social and Mental domains with increased scores of 5.1 +/- 23.3 and 5.1 +/- 17.2, respectively. All changes in scores were statistically significant when compared to baseline (P < .001).
We compared the incidence of perioperative complications among patients stratified into groups based on positive or negative changes in physical and mental health at the 1-year follow-up. A patient was considered to have a negative mental change if he or she demonstrated a decrease in HRQL at 1 year from baseline for any of these domains: mental, social, or role. A similar statistic, negative physical change, was calculated for physical domains: health, pain, or physical. Patients with a negative physical change were significantly more likely to have an increased length of stay (5.7 vs 5.2 days, P < .017), mediastinitis (0.9% vs 0.0%, P < .037), and permanent stroke (1.8% vs. 0.0%, P < .003).
Estimated survival at 2, 3, and 5 years following surgery are presented in Table 2. When stratified by positive or negative HRQL 1-year trajectory, negative HRQL patients experienced statistically significant decreased survival for all domains except Physical. Excluding the overall domain, the largest 5-year survival differences were observed for the domains of health (-9.2%), social (-8.6%), and role (-8.0%). After adjustment for the presence or absence or major preoperative parameters listed in Table 1, a negative HRQL trajectory for the domains of health (HR: 1.93; 95% CI: 1.26-2.94), social (HR: 3.40; 95% CI: 2.14-5.41), and overall (HR: 1.80; 95% CI: 1.20-2.71) was predictive of decreased survival. No other domains had statistically significant HR.
DISCUSSION
Elective open-heart surgery patients with decreasing HRQL at 1 year following cardiac surgery may experience a survival disadvantage in comparison with those patients experiencing positive gains at 1 year. This research illustrates both the strengths and weaknesses of cardiac surgical healthcare as it relates to follow-up. Currently, 2 weeks following an open-heart procedure, the patient is transferred from the cardiovascular surgeon's care back to the referring cardiologist and primary care physician. At this point, any continued formal patient follow-up initiated and directed by the hospital's cardiac surgery program ceases. It is a rare case indeed when the cardiologist and the cardiovascular surgeon communicate about the patient's status.
Previous research has demonstrated that following cardiac surgery, patients may experience negative effects such as decreased functional status,4 isolated depression,5 pain and discomfort,6,7 and decreased sleep.8 Reasons cited for decreased HRQL following cardiac surgery are traumatic experiences, for example, complications, long intensive care unit (ICU) stay and others in the ICU,9,10 poor general recovery in the hospital,11 and preoperative perceived health status.12
Furthermore, if decreased HRQL at some arbitrary postoperative time point is systematically related to the hospital for reasons such as long ICU stay or increased postoperative trauma, then such adverse outcomes should be identified and appropriate protocols enacted. However, what if decreased HRQL among mental components are not causally related to the institution or postoperative care but situations that occur postdischarge? How would these situations be identified and treated?
We have highlighted an area of need that the nursing profession is greatly suited to fill gap between surgical follow-up and the postsurgical transfer back to medical care. Perhaps decreased HRQL gains following surgery are related to unacceptably high patient expectations regarding their recovery. For example, we recently interviewed several nursing groups and discovered as part of the patient discharge education, our nursing staff frequently conveys, "You will be back to normal in 6 months." Setting aside the concept of what "normal" is, it is possible that at 6 months when patients have not yet recovered but expect to be, they may view the surgical procedure as a failure with HRQL scores so reflected.
We believe these data present an opportunity to begin a dialogue for nursing groups, both clinical and administrative, to identify ways to increase postoperative follow-up that identifies and treats potential patient failures. Most healthcare institutions regard cardiac service lines as profitable and, as such, subsequently worthy of additional resources. Postoperative nursing care that includes time beyond the immediate discharge may serve to decrease readmissions, identify patients with chronic disease who stress the healthcare system, and increase institutional image and patient satisfaction within the community.
We suggest several roles for the nursing staff:
1. Educate nursing staff on HRQOL findings and trends to allow a more realistic dialogue with the patient. Recovery is most likely not achieved in 6 months, and, in fact, some patients may take at least 1 year.
2. Identify and communicate with case management about those patients with poor HRQOL scores prior to surgery so that discussion can take place about discharge planning, social support, and follow-up strategies.
3. Introduce HRQOL discussion as part of the routine in-hospital, multidisciplinary rounds in the ICU, and step-down services.
4. Continue patient contact for 1 postoperative year. Establish a routine follow-up program that may be as detailed as HRQL assessment or as simple as a follow-up phone call.
5. Investigate use of e-mail, Internet access, tele-health, and/or tele-medicine to provide education and promote disease management and education.
Potential limitations of this study may have affected the results. By design, the patient population was restricted to elective patients only. This subgroup provided the best chance for identifying patients with a stable state of mind preoperatively. It is possible, however, that both urgent and emergent patients have increased length of stay and postoperative morbidity. However, patients with urgent or emergent status preclude any viable way to separate the presumed stable state of mind within the elective patient population versus the stress brought forth by the immediacy of their open-heart surgery. Our response rates 1 year after surgery may have affected our study's generalizability. Although low response rates undermine the validity of any survey, considering the age of our cohort, a higher response rate may not be possible. In a study of erectile function among men aged 30-80 years, Braun et al reported response rates ranging from 49.2% to 68.4% and decreasing with age.1,13 Furthermore, because we use a mailed questionnaire, the US Post Office returns all questionnaires with no forwarding address. Thus, we know that a substantial decrease in the response rate was due to patient relocation, not refusal to participate.
As the US population increases in age and the soon-to-retire "baby-boomer" wave puts additional stress on already-burdened healthcare resources, the nursing profession has the opportunity to fill a niche that currently does not exist. Open-heart surgery represents one area of healthcare that will grow through the 21st century; however, it is treated by the healthcare profession as a "be-all and end-all" approach to HRQOL. Clinical care should extend beyond the immediate postoperative period. Only the nursing profession with its clinical, holistic, and spiritual approaches to all facets of care is uniquely poised to serve this growing need.
REFERENCES