The traditional practice of conducting the first outpatient review six weeks after cardiac surgery is not evidence-based. This study was designed to determine mortality and morbidity in the interval between hospital discharge and the first outpatient follow-up.
We enrolled patients undergoing non-emergency cardiac surgery from June 2016 to May 2017 into this prospective observational study. Prior to hospital discharge, patients were consented and given a questionnaire to document attendance at any healthcare facility. Ethical approval was obtained from the Health Research Authority.
The mean age of the 72 study patients was 68 ± 4 years. The majority underwent coronary artery bypass grafting (56.9%). The six-week postoperative morbidity rate was 38.9% and hospital readmission 15.3%. Morbidity, highest in the first week after discharge, declined to its lowest level by four weeks. Surgical site (13.9%) and respiratory complications (13.9%) were predominant causes of late morbidity. There was no mortality. Most patients (50%) expressed satisfaction with current practice, but a significant number (44.4%) would prefer earlier review.
In conclusion, morbidity during the six-week wait for the first outpatient review after cardiac surgery is not insignificant, but declines over time. Current practice does not seem to enable a positive specialist influence of the post-surgery recovery pathway.
Clinical Trials.gov registration number: NCT02832427
In the UK, over 35,000 cardiac operations are performed annually.1 Traditionally, patients who have undergone cardiac surgery return to the outpatient clinic for their first postoperative review by the specialist team six weeks after hospital discharge. There is no evidence to show that six weeks is the optimal interval before these patients, with ongoing risks of postoperative complications, are reviewed. Not infrequently, after hospital discharge, cardiac surgery patients make unplanned hospital visits and/or require readmission during the six-week wait for outpatient review, due to surgery-related complications.2-4 While readmission rates within 30 days are well reported, outpatient treatment at hospitals and/or GP surgeries, by patients with less severe complications that do not require admission are not usually reported.
Thirty-day readmission and mortality rates are widely used as indicators of the quality of surgical care,5,6 and 30-day hospital readmission rates after cardiac surgery as high as 20.9% have been reported.7 It can be argued that the long interval between hospital discharge and the first outpatient specialist review exposes patients to ongoing risks of surgery-related complications. Postoperative programmes that have incorporated early contact by the cardiac team with patients have reported significant reduction in hospital readmissions.8
Hospital readmissions and repeated visits to the hospital or GP surgeries contribute significantly to healthcare costs while compromising the quality of care.9,10 Consequently, factors contributing to hospital readmissions have been extensively studied and strategies described to reduce 30-day readmissions, but these have focused mainly on the management of predictors of readmission.11-16 Risk factors that cannot be modified such as older age and comorbidities, which are prevalent among patients undergoing cardiac surgery in the current era,17 are even stronger reasons to re-examine the long-standing six-week outpatient follow-up practice.
The aim of this single-centre prospective observational study was to examine postoperative complications experienced by cardiac surgery patients during the interval between hospital discharge and the first planned outpatient review.
Materials and method
This is a single-centre prospective observational study conducted from June 2016 to May 2017. On admission for surgery, prospective patients were approached and provided with study information. From the third postoperative day, eligible patients were consented and given a one-page questionnaire to complete themselves or by their spouse/carer, in real time, during the interval between hospital discharge and outpatient review. They were asked to return the completed questionnaire at their outpatient appointment, or soon thereafter, by post in an attached stamped-envelope. Telephone calls were made to remind patients to return the questionnaire in some cases. The questionnaire was designed to allow for self-reporting of presentations to hospital ward, emergency department or GP surgery. There was also a section inviting feedback about their satisfaction with the six-week wait for follow-up. Patients who were undergoing coronary artery bypass grafting (CABG), heart valve repair or replacement, combined CABG and heart valve surgery, and aortic root/ascending replacement were included. Patients with impaired memory, postoperative stroke with neurological deficit, and those who had prolonged hospital stay (>14 days) due to postoperative complications were excluded.
The catchment area for our hospital covers up to a 50-mile radius, so after hospital discharge, a cardiac physiotherapist makes a routine telephone call to patients as part of the phase II cardiac rehabilitation programme.
Pre-operative and peri-operative data were collected using our standard cardiothoracic surgery electronic database programme, as is routine at our institution. In addition, post-discharge data relating to unplanned hospital attendance and/or readmission, and any intervention by a GP or GP surgery nurse during the six-week interval before the first planned specialist review, was prospectively collected using the questionnaire.
We also conducted a telephone survey of the cardiac surgery centres in the UK to confirm the timing of their first planned post-cardiac surgery follow-up outpatient review.
The primary objectives of the study were to:
- Report the rates of postoperative mortality, morbidity, unplanned further interventions and readmission that occur in the six-week interval between hospital discharge and the first planned specialist review.
- Determine the timing of these adverse outcomes.
The secondary study objective was to assess patients’ level of satisfaction with the current six-week interval for their first planned outpatient review post-hospital discharge.
Categorical variables are reported as percentages and continuous variables as mean ± standard deviation (SD). Rates of different complications were determined and the timing of the complications/intervention presented as a frequency plot.
A total of 85 consecutive patients were enrolled into the study, however, the study questionnaire was received from 72 patients (84.7%). The clinical details of the 72 patients are shown in table 1. The mean age of the study population was 68 ± 9 years and 12 of these were female (16.7%). The majority of patients underwent CABG (n=41, 56.9%) and the average length of hospital stay was 8 ± 4 days.
During the six-week interval between hospital discharge and the first planned outpatient appointment, 28 patients (38.9%) attended a healthcare facility for an unplanned consultation with either their GP or nurse, or medical doctor at a district hospital or tertiary centre due to postoperative morbidity. Twelve patients (16.9%) attended the accident and emergency department. The hospital readmission rate between hospital discharge and the first planned outpatient review was 15.3% (n=11), and this was predominantly in patients discharged after six days (n=7). The most common postoperative morbidities leading to unplanned attendance at a healthcare facility (figure 1) were surgical site infection (n=10, 13.9%) and respiratory complications, such as pleural effusion and pulmonary embolism (n=10, 13.9%). The surgical site infection involved the leg donor wounds in nine patients; one of these, and another patient also had superficial sternal wound infection. There was no mortality during the six-week interval.
Figure 2 depicts the timings of postoperative complications occurring in the six-week intervening period between hospital discharge and the first planned outpatient review. The incidence of postoperative complications was highest in the first week after discharge and declined progressively with time to very low incidence by four weeks. The complications that occurred after four weeks were mainly related to the original pathology, such as heart failure related, or exacerbation of co-existing medical conditions, like chronic obstructive pulmonary disease or gout.
Although half the study patients (n=36, 50%) accepted the six-week interval between hospital discharge and the first planned outpatient review as satisfactory, a significant proportion (n=32, 44.4%) would prefer a shorter interval (figure 3). It is noteworthy that eight out of those who were satisfied with current practice suggested that perhaps an earlier telephone contact by the healthcare team could help either to reassure, or alleviate anxiety that could arise from occasional feelings of pain or discomfort during the recovery process, or detect early signs of late complications. None of the patients felt that the six-week interval was too short.
A telephone survey conducted in May/June 2017 of 35 out of 42 UK cardiac centres confirmed that the standard practice in all the 35 centres was to conduct the first planned outpatient review at six weeks after hospital discharge. In practice, the wait for outpatient review was even longer at four centres.
The timing of the first postoperative review after cardiac surgery is crucial in facilitating patient recovery. Apart from providing an opportunity to alter medical management to prevent or interrupt postoperative complication, it allows for the assessment of fitness to resume usual activities like driving, and enables early release to commence exercise-based cardiac rehabilitation, which positively impacts recovery after cardiac surgery.18-19 The traditional practice of conducting the first planned outpatient review at six weeks after cardiac surgery, as confirmed by our survey, is not substantiated by clinical evidence, and may delay important aspects of postoperative aftercare like cardiac rehabilitation, and prolong the recovery process. Our study shows that a sizeable proportion of patients (38.9%) develop postoperative complications in the six-week interval between hospital discharge and the first outpatient review, and 39% of these attended the accident and emergency department and were readmitted into hospital. The six-week hospital readmission rate of 15.3% sits well within the range for 30-day readmission rates after cardiac surgery. Lahey et al.7 reported a 30-day readmission rate of 20.9%, and the series of Stewart and associates11 found a 30-day readmission rate of 16%, after cardiac surgery. The six-week readmission rate in our study compares well with the reported 30-day (four weeks) readmission rates, and this supports our finding that most, if not all, of the major complications requiring hospital readmission occur in the first four weeks after hospital discharge. It is arguable that an earlier outpatient review could reduce the late morbidity rate, both directly and indirectly, through early referral to cardiac rehabilitation, which is known to facilitate recovery post-cardiac surgery.18,19 It remains uncertain why six weeks is chosen for the first outpatient review after cardiac surgery, but, in light of the findings of this study, the rationale for this time interval is questionable.
Surgical site infection and respiratory complications, such as pleural effusion and pulmonary embolism, were the predominant causes of late postoperative morbidity. For the most part, these complications are preventable. Leg donor site infection was the predominant surgical site infection observed in our study. In our series, open leg vein harvesting was used in all patients undergoing CABG; perhaps endoscopic vein harvesting would have reduced the rate of late donor site infection, as has been widely reported,20 and facilitated early mobility and better quality of life,21 with a potential to reduce the risk of postoperative pulmonary embolism.
A significant proportion of patients who have undergone cardiac surgery would be reassured if they are either reviewed or contacted by telephone earlier than six weeks after hospital discharge. Studies have shown that, apart from physical complications of surgery, cardiac surgery patients also suffer from psychological morbidity like anxiety,22 and the six-week wait for specialist review may not afford timely management or appropriate referral.
The small study sample size limits our ability to draw associations and correlations between independent variables and outcomes of interest. Also, as the study design is not a randomised-controlled trial, we were not able to compare late postoperative morbidity between early review and traditional six-week review groups in order to determine if earlier outpatient review would lead to better outcomes. However, the prospective observational study design provides the ‘real-world’ experience of current practice and has enabled us to generate the hypothesis for a National Institute for Health Research (NIHR)-funded randomised-controlled trial, into which we will start recruiting from early 2019.
This prospective observational study shows that the postoperative morbidity rate in the six-week interval between hospital discharge and the first planned outpatient review is not insignificant. The proclivity to developing postoperative complications after cardiac surgery steadily diminishes over time following hospital discharge. The traditional planned six-week postoperative review does not afford the best possible opportunity to positively influence the postoperative recovery. Further studies are needed to determine the optimal timing of postoperative review to facilitate a faster and less complicated recovery.
The study was funded by Hull and East Yorkshire Hospitals NHS Trust.
Ethical approval was obtained from the Health Research Authority.
Conflicts of interest
- The traditional practice of conducting the first planned postoperative outpatient review six weeks after cardiac surgery is not evidence-based
- Significant morbidity occurs during this period, and commencement of cardiac rehabilitation is delayed
- The traditional timing of first outpatient review after cardiac surgery does not facilitate optimal postoperative care and recovery
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