Abstract
In this study, we investigated the early and long-term results of conventional aortic valve replacement (AVR) in very old patients.
Methods: Seventy-five patients with aortic stenosis underwent conventional AVR for patients aged 80 years.We examined early death and major adverse cardiovascular and cerebrovascular event (MACCE).
Results: The operative mortality was 0% for isolated AVR and 19.2% for concomitant surgery. The postoperative survival rate and MACCE free-rate were no significant differences between the isolated AVR and the concomitant surgery. Univariate analysis confirmed that cardiac dysfunction, severe chronic kidney disease (CKD), hemodialysis, + coronary artery bypass grafting, and norepinephrine use were risk factor of early death. Univariate analysis confirmed that severe CKD, BNP >1000 pg/ml, aortic cross clamping time (ACCT) >180 min, and non-use carperitide and multivariate analysis confirmed that ACCT >180 min, and non-use carperitide were risk factor of MACCE.
Conclusions: This study showed that the results of conventional AVR in very old patients were not satisfactory. However, the results obtained with isolated AVR were favorable with no operative deaths. The present study demonstrated that preoperative cardiac function, preoperative renal function, and operative factors have an important impact on early mortality and MACCE.
Keywords: aortic valve replacement, elderly, octogenarians
Introduction
Aging of the Japanese population has become the most rapid worldwide. In addition, the average life expectancy is longer in Japan than in the USA and Europe, so the number of elderly patients undergoing cardiac surgery is increasing.1–3) The criteria for performing cardiac surgery in elderly patients have not been defined, but we need to consider medical problems such as an increased rate of cerebral complications and dementia compared to younger patients as well as social aspects such as medical costs or nursing care. There is an increasing number of elderly patients with valvular aortic stenosis and conventional aortic valve replacement (AVR) is performed for most of them, but the results are inferior compared with those obtained in younger patients. Following the development of transcatheter aortic valve implantation (TAVI), efficacy in patients for whom conventional AVR is not indicated has been reported.4–6) However, there is insufficient data on the efficacy of TAVI in various subgroups of patients, such as Japanese women who tend to have a narrow valve ring. Progress inoperative procedures and postoperative management allows surgery to be performed in very old patients, but there is an urgent need to determine the indications and identify problems. If elderly patients who have aortic valve disease are judged to be unlikely to reach their average life expectancy with drug therapy, the policy of our Department is to suggest surgery based on the following conditions: (1) the patient is at risk of dying and the family gives consent; (2) the patient and his/her family gives consent and the patient has few complications, is still active, and considered able to tolerate surgery based on preoperative examination. Thus, we do not use age itself as a determinant of surgery. In this study, we investigated the early and long-term results of conventional AVR in very old patients (aged 80 years or older).
Patients and Methods
Seventy-five patients with aortic stenosis underwent conventional AVR for octogenarians at Nihon University Itabashi Hospital between 2000 and 2013. Preoperative background and intraoperative and postoperative factors of the 75 patients are summarized in Table 1. The preoperative factors examined were an age ≥85 years, gender, NYHA class IV, hypertension, diabetes mellitus, dyslipidemia, obesity, smoking, chronic obstructive pulmonary disease, re-operation, cardiac dysfunction (EF <35%), severe chronic kidney disease (CKD; eGFR <30 ml/min/1.73 m2), hemodialysis, cerebrovascular disease, BNP >1000 pg/ml, urgent surgery. Intraoperative factors examined were isolated AVR, + coronary arterial bypass grafting (CABG), aortic cross clamping time ≥180 min, and intraoperative use of catecholamine and carperitide. We examined early death and major adverse cardiovascular and cerebrovascular event (MACCE). Logistic regression analysis was conducted using preoperative and intraoperative factors in relation to the early death and MACCE.
Table 1.
Patient’s characteristics
| Number | 75 |
| Age (years) | 82.3 ± 2.3 (80–90) |
| ≥85 years | 11 (15%) |
| Gender (male: female) | 36:39 |
| BSA (m2) | 1.47 ± 0.16 |
| Pre NYHA class I | 2 (3%) |
| II | 21 (28%) |
| III | 35 (47%) |
| IV | 17 (22%) |
| Aortic stenosis | 35 (47%) |
| Aortic regurgitation | 12 (16%) |
| Aortic stenosis and regurgitation | 28 (37%) |
| Risk factors | |
| Diabetes mellitus | 18 (24%) |
| Hypertension | 52 (69%) |
| Dyslipidaemia | 23 (31%) |
| Obesity | 9 (12%) |
| Smoking | 12 (14%) |
| COPD | 4 (5%) |
| Cardiac dysfunction (EF <40%) | 15 (20%) |
| Ejection fraction (%) | 58.3 ± 14.0 |
| CKD (eGFR <60 ml/min/1.73 m2) | 51 (68%) |
| eGFR <30 ml/min/1.73cm2 | 12 (16%) |
| Hemodialysis | 7 (9%) |
| eGFR (ml/min/1.73 cm2) | 51.3 ± 24.2 |
| Serum Creatine (mg/dl) | 1.60 ± 2.14 |
| Cerebral infarction | 6 (8%) |
| Urgent | 4 (5%) |
| Reoperation | 3 (4%) |
BSA: body surface area; COPD: chronic obstructive pulmonary disease; EF: ejection fraction; CKD: chronic kidney disease; eGFR: estimated glomerular filtration rate
This was a retrospective study with a 96.0% follow-up rate, and a mean follow-up period of 4.3 ± 2.8 years (maximum: 14.3 years).
Statistical Analysis
Data are expressed as the mean ± the standard deviations (SD). For statistical analysis, univariate logistical regression analysis of the pre- and intra-operative factors was performed. Variables showing significance were then subjected to multivariate analysis. The overall mortality rate and MACCE free rate were determined by the Kaplan-Meier method. Student’s t-test and Fisher’s exact test were used for other statistical analyses. A probability (p) value of less than 0.05 was considered to indicate statistical significance.
Results
Early results
The overall operative mortality rate was 6.7% (n = 5) and all death cases were patients having concomitant surgery. The operative mortality was 0% for patients having isolated AVR and 19.2% (n = 5) for patients having concomitant surgery (AVR + coronary artery bypass grafting (CABG) in two cases, AVR + mitral valve replacement (MVR) + CABG, AVR + mitral valve annuloplasty (MVP) + CABG, and AVR + MVR in each 1 case) (Table 2).
Table 2.
Operative data
| Number | 75 |
| Bio-prosthesis | 73 (97%) |
| Mechanical-prosthesis | 2 (3%) |
| Aortic root enlargement | 1 (1%) |
| Size of prosthesis | |
| 16 mm | 1 (1%) |
| 17 mm | 1 (1%) |
| 19 mm | 26 (35%) |
| 21 mm | 31 (41%) |
| 23 mm | 13 (17%) |
| 25 mm | 3 (4%) |
| Isolated aortic valve replacement | 49 (65%) |
| Concomitant surgery | 26 (35%) |
| CABG | 18 (24%) |
| Mitral valve replacement | 7 (9%) |
| Mitral annuloplasty | 2 (3%) |
| Trisupid annuloplasty | 3 (4%) |
| Asc-Ao replacement | 3 (4%) |
| Maze | 3 (4%) |
| ACCT (min) | 96.9 ± 43.3 |
| ACCT ≥120 min | 16 (21%) |
| ECCT (min) | 147.3 ± 58.3 |
| ECCT ≥180 min | 17 (23%) |
| Dopamine use | 61 (81%) |
| Dobutamine use | 41 (55%) |
| Epinephrine use | 14 (19%) |
| Norepinephrine use | 8 (11%) |
| Carperitide use | 36 (48%) |
Asc-Ao: ascending aorta; CABG: coronary artery bypass grafting; ACCT: aortic cross clamping time; ECCT: extracorporeal circulation time
The cause of death was low output syndrome (LOS) in four cases and heart failure in one case. All five patients who died were high risk preoperatively with the following risk factors: NYHA class III or higher in three patients (class IV in 2), hypertension in four patients, cardiac dysfunction in four patients, severe CKD in four patients, and hemodialysis in three patients. In addition, concomitant surgerywas performed in all five patients (including CABG in 4). The perioperative complication occurred in 16 patients. The cause of complication was LOS in six cases and heart failure in three cases, atrioventricular block in two cases, and respiratory failure and pneumonia and mediastinaitis and bleeding and urinary tract infection in one case each.
Late results and MACCE
There were 11 late deaths, with the cause being cerebral infarction and pneumonia in three cases each, heart failure in three cases, and malignancy and sudden death in one case each. The MACCE was 26 cases. The cause of MACCE was death in 16 cases (early; five cases, late; 11 cases), heart failure and atrioventricular block in three cases each, cerebral bleeding two cases, LOS and cerebral infarction in 1 case each.
The postoperative 1-year survival rate was 85.3 ± 4.1%, the 3-year survival rate was 68.0 ± 5.4%, the 5-year survival rate was 42.7 ± 5.7%, the 8-year survival rate was 12.0 ± 3.8%, and the 10-year survival rate was 2.7 ± 1.9% (Fig. 1). In isolated AVR, the postoperative 1-year survival rate was 90.5 ± 4.5%, the 3-year survival rate was 69.0 ± 7.1%, the 5-year survival rate was 45.2 ± 7.7%, the 8-year survival rate was 19.0 ± 6.1%, and the 10-year survival rate was 4.8 ± 3.3%. In concomitant surgery, the postoperative 1-year survival rate was 78.8 ± 7.1%, the 3-year survival rate was 66.7 ± 8.2%, the 5-year survival rate was 39.4 ± 8.5%. There were no significant differences between the isolated AVR and the concomitant surgery (p = 0.320) (Fig. 1).
Fig. 1.
Overall actuarial survival rate and MACCE free rate (upper) and actuarial survival rate and MACCE free rate in isolated aortic valve replacement and concomitant surgery (lower). MACCE: major adverse cardiovascular and cerebrovascular event; AVD: aortic valve replacement
The postoperative 1-year MACCE event-free rate was 74.7 ± 5.0%, the 3-year MACCE event-free rate was 58.7 ± 5.7%, the 5-year MACCE event-free rate was 34.7 ± 5.5%, the 8-year MACCE event-free rate was 9.3 ± 3.4%, and the 10-year MACCE event-free rate was 2.7 ± 1.9% (Fig. 1). There were no significant differences between the isolated AVR and the concomitant surgery (p = 0.482) (Fig. 1).
Analysis of the early all cause death revealed the following risk factors (Table 3)
Univariate analysis confirmed that cardiac dysfunction (p = 0.009), severe CKD (p = 0.004), hemodialysis (p = 0.002), +CABG (p = 0.002), and norepinephrine use (p = 0.004) were risk factors. Multivariate analysis did not identify any risk factors. Since there were no early deaths after isolated AVR, statistical analysis could not be performed. Among the seven patients on hemodialysis, there were three early deaths and there was also one late death due to pneumonia at 5 months after surgery.
Table 3.
Preoperative, intraoperative and postoperative factors and early death
| Univariate | Multivariate | |||
|---|---|---|---|---|
| Odds ratio (95% CI) | p value | Odds ratio (95% CI) | p value | |
| Preoperative factors | ||||
| Age ≥85 years | – | – | ||
| Gender (male) | 0.71 (0.11–4.49) | 0.711 | ||
| Pre NYHA IV | 2.44 (0.37–16.0) | 0.338 | ||
| Hypertension | 1.83 (0.19–17.4) | 0.592 | ||
| Diabetes mellitus | 5.50 (0.84–36.0) | 0.075 | ||
| Dyslipidaemia | 0.55 (0.06–5.17) | 0.592 | ||
| Obesity | 1.94 (0.19–19.6) | 0.569 | ||
| Smoking | 1.34 (0.14–13.2) | 0.801 | ||
| COPD | 5.58 (0.47–66.5) | 0.131 | ||
| Re-operation | 8.50 (0.63–114.9) | 0.107 | ||
| Cardiac dysfunction (EF <35%) | 21.5 (2.19–210.6) | 0.009 | 18.6 (0.83–418.7) | 0.658 |
| Severe CKD (eGFR <30 ml/min/1.73m2) | 31.0 (3.07–312.8) | 0.004 | 0.67 (0.004–103.6) | 0.877 |
| Hemodialysis | 24.8 (3.17–193.1) | 0.002 | 19.2 (0.09–4265.1) | 0.284 |
| Cerebrovascular disease | 3.25 (0.30–34.9) | 0.306 | ||
| BNP >1000 pg/ml | 6.00 (0.91–39.4) | 0.062 | ||
| Urgent | 5.58 (0.47–66.5) | 0.174 | ||
| Intraoperative factors | ||||
| ACCT ≥180 min | 6.00 (0.91–39.4) | 0.062 | ||
| Isolated AVR | – | – | ||
| + CABG | 16.0 (1.66–154.6) | 0.002 | 19.2 (0.49–1728.3) | 0.105 |
| Dopamine | 0.97 (0.33–2.99) | 0.268 | ||
| Dobutamine | 0.79 (0.12–5.04) | 0.805 | ||
| Norepinaphrine | 19.5 (2.62–145.1) | 0.004 | 20.3 (0.47–881.9) | 0.118 |
| Carperitide | 0.67 (0.11–4.24) | 0.666 | ||
COPD: chronic obstructive pulmonary disease; EF: ejection fraction; CKD: chronic kidney disease; eGFR: estimated glomerular filtration rate; BNP: brain natriuretic peptide; ACCT: aortic cross clamping time; AVR: aortic valve replacement; CABG: coronary arterial bypass grafting
Analysis of MACCE revealed the following risk factors (Table 4)
Univariate analysis confirmed that severe CKD (p = 0.041), BNP >1000 pg/ml (p = 0.038), ACCT >180 min (p = 0.023), and non-use carperitide (p = 0.037) were risk factor. Multivariate analysis confirmed that ACCT >180 min (p = 0.035), and non-use carperitide (p = 0.036) were risk factor.
Table 4.
Preoperative, intraoperative and postoperative factors and MACCE
| Univariate | Multivariate | |||
|---|---|---|---|---|
| Odds ratio (95% CI) | p value | Odds ratio (95% CI) | p value | |
| Preoperative factors | ||||
| Age ≥85 years | 0.37 (0.07–1.86) | 0.214 | ||
| Gender (male) | 0.33 (0.16–1.16) | 0.091 | ||
| Pre NYHA IV | 1.98 (0.66–5.95) | 0.222 | ||
| Hypertension | 1.77 (0.60–5.24) | 0.299 | ||
| Diabetes mellitus | 1.27 (0.43–3.81) | 0.666 | ||
| Dyslipidaemia | 1.73 (0.63–4.77) | 0.286 | ||
| Obesity | 0.94 (0.21–4.09) | 0.929 | ||
| Smoking | 0.93 (0.25–3.44) | 0.916 | ||
| COPD | 0.61 (0.06–6.21) | 0.676 | ||
| Re-operation | 0.94 (0.08–10.9) | 0.960 | ||
| Cardiac dysfunction (EF <35%) | 1.89 (0.60–5.97) | 0.275 | ||
| Severe CKD (eGFR <30 ml/min/ 1.73m2) | 3.24 (1.07–11.5) | 0.041 | 2.47 (0.58–10.5) | 0.221 |
| Hemodyalysis | 2.79 (0.57–13.5) | 0.189 | ||
| Cerebrovascular disease | 2.00 (0.37–10.7) | 0.411 | ||
| BNP >1000 | 2.71 (1.09–8.21) | 0.038 | 2.49 (0.69–9.00) | 0.164 |
| Urgent | 6.26 (0.92–63.5) | 0.081 | ||
| Intraoperative factors | ||||
| ACCT ≥180 min | 2.71 (0.90–8.21) | 0.023 | 3.78 (1.10–13.0) | 0.035 |
| Isolated AVR | 0.69 (0.27–1.80) | 0.446 | ||
| + CABG | 2.35 (0.80–6.96) | 0.117 | ||
| Dopamine | 0.95 (0.28–3.18) | 0.927 | ||
| Dobutamine | 0.65 (0.25–1.72) | 0.384 | ||
| Norepinaphrine | 3.65 (0.80–16.7) | 0.080 | ||
| Carperitide | 0.40 (0.14–0.92) | 0.037 | 0.30 (0.10–0.92) | 0.036 |
MACCE: major adverse cardiovascular and cerebrovascular event; COPD: chronic obstructive pulmonary disease; EF: ejection fraction; CKD: chronic kidney disease; eGFR: estimated glomerular filtration rate; BNP: brain natriuretic peptide; ACCT: aortic cross clamping time; AVR: aortic valve replacement; CABG: coronary arterial bypass grafting
Discussion
This study showed that the results of conventional AVR in very old patients were not satisfactory. However, the results obtained with isolated AVR were favorable with no operative deaths. Shan et al. reviewed the literature on AVR in elderly patients and reported that the overall early mortality rate of patients aged 80 years or older undergoing AVR was 4.9%–16.7%, the early mortality rate after isolated AVR was 4.3%–10.2%, and the early mortality rate after AVR + CABG was 5.4%–25.7%.7) In our study, the early mortality rate after isolated AVR was 0%, while the early mortality rate after AVR + concomitant surgery was 19.1% (11.8% for AVR + CABG), which are more acceptable results compared with those in the above report. Although the early mortality rate after AVR + concomitant surgery was unfavorable compared with that for isolated AVR, the long-term results were acceptable in patients who tolerated surgery. For patients with other diseases that also require surgery, a conclusion has not been reached based on the previous literature about whether AVR should be performed alone or with additional surgery. Shan et al. suggested that doctors should be encouraged to evaluate potential patients for AVR surgery on the basis of their comorbidities rather than using age as a deciding factor.7) Dell’Amore et al. investigated AVR with and without CABG in elderly patients and reported that the incidence of LOS was significantly higher in patients having concomitant CABG, but there was no influence on hospital mortality and long-term survival. Instead, they found that the urgency status, EF <35%, intraoperative variables (such as the clamping time and need for an intra-aortic balloon pump) and postoperative variables (such as prolonged ventilation, dialysis, postoperative myocardial infarction, and repeat thoracotomy for bleeding) had an influence on hospital mortality.8)
Although there have been few reports regarding AVR in Japanese elderly patients, Handa et al. investigated 7883 patients undergoing isolated AVR in the Japan Adult Cardiovascular Surgery Database. They found that operative mortality andthe incidence of postoperative complications (stroke, respiratory problems, transient ischemic attack (TIA), renal failure, multiple organ failure, etc.) were significantly higher in patients aged 80 years or older (n = 1,014) than in patients aged 79 years or younger, and the risk factors for operative mortality were urgent surgery, emergency surgery, preoperative arrhythmia, 3-vessel coronary artery disease, respiratory insufficiency, tricuspid regurgitation, dialysis, unexpected CABG, and current smoking.3) Aoyagi et al. studied 60 octogenarians undergoing heart valve surgery and reported that urgent operation, preoperative NYHA class IV, preoperative renal dysfunction, perioperative use of an intra-aortic balloon pump, and prolonged cardiopulmonary bypass had an influence onoperative mortality.9)
While the present study suggested that the indications for surgery should not be determined by age alone, severe CKD was found to be a strong contraindication with a 6-month mortality rate of 57.1%. Thus, TAVI should probably be considered for dialysis patients although it is not indicated for these patients at present. Preoperative cardiac dysfunction and concomitant surgery including CABG also had an influence on early mortality. In addition to preoperative severe CKD and cardiac dysfunction, prolonged aortic clamping and non-use of carperitide had an effect on long-term MACCE. Our clinical research on perioperative low-dose infusion of carperitide has demonstrated that this drug compensates for the deficiencies of cardiopulmonary bypass and also provides organ protection,10,11) with both effects being stronger in high risk patients.12) Accordingly, administration of carperitide to elderly patients undergoing cardiac surgery could be effective for decreasing postoperative complications and protecting vital organs. In elderly patients undergoing cardiac surgery, postoperative complications have a major influence on mortality. Among the postoperative complications occurring after cardiac surgery in patients aged 80 years or older, Kamiya et al. reported that mortality was influenced by acute renal failure, LOS, sepsis, prolonged respiratory failure with tracheotomy, repeat thoracotomy due to bleeding, and postoperative laparotomy.13) An investigation of elderly patients undergoing AVR by Hosono et al. revealed that the preoperative left ventricular mass index, lack of sinus rhythm, peak transvalvular pressure gradient <60 mmHg, and liver cirrhosis were factors with an effect on late valve-related mortality.14)
Because the present study demonstrated that preoperative cardiac function, preoperative renal function, and operative factors have an important impact on early mortality and MACCE, it may be desirable to perform surgery before symptomatic deterioration (during the asymptomatic period) by strengthening cooperation between cardiovascular physicians and general practitioners. In addition, appropriate perioperative medical therapy should be provided to reduce postoperative complications related to cardiopulmonary bypass and other complications such as cerebral infarction and renal failure.15–17)
Conflict of Interest Statement
Akira Sezai received lecture fees from Dai-ichi Sankyo Co., Ltd. The other authors have no conflict of interest.
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