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Eur J Cardiothorac Surg 2005;27:887-892
© 2005 Elsevier Science NL

Timing of intra-aortic balloon pump support and 1-year survival

Ian R. Ramnarinea, Antony D. Graysonb,*, Walid C. Dihmisa, Neeraj K. Medirattaa, Brian M. Fabria, John A.C. Chalmersa

a Department of Cardiothoracic Surgery, The Cardiothoracic Centre, Liverpool, UK
b Department of Clinical Governance, The Cardiothoracic Centre, Thomas Drive, Liverpool L14 3PE, UK

Received 9 November 2004; received in revised form 31 January 2005; accepted 2 February 2005.

* Corresponding author. Tel.: +44 151 293 2336; fax: +44 151 288 2371. (E-mail: tony.grayson{at}ctc.nhs.uk).


   Abstract
Top
 Abstract
1. Introduction
 2. Methods
 3. Results
 4. Discussion
 References
 
Objective: The relationship between the timing of intra-aortic balloon pump (IABP) support and surgical outcome remains a subject of debate. Peri-operative mechanical circulatory support is commenced either prophylactically or after increasing inotropic support has proved inadequate. This study evaluates the effect timing of IABP support on the 1-year survival of patients undergoing cardiac surgery. Methods: From April 1997 to September 2002, 7698 consecutive cardiac surgical procedures were performed. This included 5678 isolated coronary artery bypasses (CABGs), 1245 isolated valve procedures and 775 simultaneous CABG and valve procedures. IABP support was required in 237 patients (3.1%). Twenty-seven patients (0.35%) were classed as high-risk and received preoperative IABP support, 25 patients (0.32%) were haemodynamically compromised and required preoperative IABP support, 120 patients (1.56%) required intra-operative IABP support, and 65 patients (0.84%) required post-operative IABP support. Multiple variables were offered to a Cox proportional hazards model and significant predictors of 1-year survival were identified. These were used to risk adjust Kaplan–Meier survival curves. Results: 1-year follow-up was complete and 450 deaths (5.8%) were recorded. The significant independent predictors of increased mortality at 1-year (P<0.05, HR=hazard ratio) were post-operative renal failure (HR=3.5), increasing EuroSCORE (HR=1.2), post-operative myocardial infarction (HR=3.7), post-operative IABP (HR=4.1) intra-operative IABP (HR=2.8), post-operative stroke (HR=2.5), increasing number of valves (HR=1.6), ejection fraction <30% (HR=1.3) and triple-vessel disease (HR=1.3). After risk-adjustment, 1-year survival for patients who required intra-operative IABP support was significantly greater than for those patients who required IABP support in the post-operative period. Conclusions: Patients who warrant IABP support in the post-operative setting have a significantly increased mortality at 1-year when compared to any other group. Therefore, earlier IABP support as part of surgical strategy may help to improve the outcome.

Key Words: IABP support • CABG • Valve surgery • Mortality


   1. Introduction
Top
 Abstract
 1. Introduction
2. Methods
 3. Results
 4. Discussion
 References
 
For nearly 40 years the intra-aortic balloon pump (IABP) has been successfully used for the treatment of peri-operative low cardiac output. It provides circulatory assist and allows the heart to rest and recover following injury. Improvements in myocardial protection, surgical and anaesthetic techniques and in IABP design have all contributed to better surgical results. This has led to older and sicker patients having operations [1]. Despite the large volume of published work supporting the use of the IABP for peri-operative circulatory support, it remains difficult to clearly identify who would derive the most benefit and to determine the optimum timing for IABP support.

There exists a clear distinction between those haemodynamically stable patients with a high estimated pre-operative risk who have an IABP inserted prophylactically and those patients who are haemodynamically compromised who require therapeutic IABP support to enable them to survive until surgery. The requirement for IABP support to wean from bypass or in the post-operative period suggests that severe cardiac injury has already occurred.

This study was undertaken on patients who had coronary revascularisation and/or valvular heart surgery over the last 5 years in a single institution. We performed an evaluation of the effect timing of IABP support had on 1-year survival.


   2. Methods
Top
 Abstract
 1. Introduction
 2. Methods
3. Results
 4. Discussion
 References
 
2.1. Patient population and data
Between April 1997 and September 2002, we studied 7698 consecutive patients undergoing coronary revascularisation and/or valvular heart operations at our institution. Isolated coronary artery bypass surgery (CABG) was performed on 5678 (74%) patients while 1245 (16%) received surgery to one or more valve, and 775 (10%) received simultaneous CABG and valve surgery. All other surgical procedures (such as post-infarction ventricular septal repair, cardiac tumour resection and surgery of the aorta) were excluded from the study.

Preoperative (Table 1), operative (Table 2) and post-operative (Table 3) data were collected prospectively in our cardiac surgery registry, as part of routine clinical practice. Methods of data collection have previously been published [2]. A retrospective case note review was carried out to collect additional information on indication for, timing of and complications of IABP support.


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  		Table 1. Preoperative characteristics
 

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  		Table 2. Operative characteristics
 

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  		Table 3. Post-operative characteristics
 
In-hospital mortality was defined as death within the same hospital admission regardless of cause. All patients transferred from the base hospital to another hospital were followed up to confirm their status at discharge. Post-operative stroke was defined as a new focal neurological deficit and/or comatose state that occurred post-operatively and persisted for more than 24h after its onset. Confused states, transient events and intellectual impairment were excluded from our study to avoid any subjective bias. Post-operative myocardial infarction was defined as a new Q-wave post-operatively in two or more contiguous leads on an electrocardiogram or a significant rise in post-operative cardiac enzymes combined with haemodynamic and echocardiographic signs of myocardial infarction. Post-operative bleeding was defined as bleeding that required surgical re-exploration after initial departure from the operating theatre. Renal failure was defined as patients with a post-operative creatinine level greater than 200µmol/L or patients requiring dialysis. Sternal wound infection was defined in accord with the published evidence-based guidelines by the Centres for Disease Control and Prevention [3]. The definition of IABP-related complications from the Benchmark registry [4] were used. Major limb ischemia was defined as loss of pulse, loss of sensation, abnormal limb temperature or pallor requiring surgical intervention.

2.2. IABP support and timing of insertion
A total of 237 (3.08%) patients received IABP support. They were allocated into groups based on the timing of the IABP insertion:

Group A: No IABP support—7461 patients (96.92%)
Group B: Preoperative IABP support in high-risk patients—27 patients (0.35%)
Group C: Preoperative IABP support in haemodynamically compromised patients—25 patients (0.35%)
Groups D: Intra-operative IABP support—120 patients (1.54%)
Groups E: Post-operative IABP support—65 patients (0.84%)
Individual surgeons decided which patient had a sufficiently high preoperative risk to warrant prophylactic IABP support (Group B). No protocol was used and IABPs were inserted after fluid and inotropes failed to result in adequate cardiac output.

All IABPs were supplied by Datascope (New Jersey, USA). The balloon size was either 34 or 40ml and were all either 8.5 or 9 French. Open and percutaneous techniques via the femoral artery were used for IABP insertion in all cases.

2.3. One-year survival
Patient records were linked to the National Strategic Tracing Service (NSTS), which records all deaths in the United Kingdom. To establish current vital status for the patient population at 1-year, patients were matched to the NSTS based on patient name, National Health Service number, date of birth, gender, and postcode. Follow-up at 1-year was complete.

2.4. Statistical methods
Due to the non-normality of continuous variables, data are shown as median, except for number of grafts and valves which are shown as a mean value (because of the low averages). Categorical variables are shown as a percentage. Comparisons were made with Kruskal–Wallis and Chi-square tests as appropriate. The European System for Cardiac Operative Risk Evaluation (EuroSCORE) was derived to assess differences in patient case-mix [5]. Deaths occurring as a function of time are described using Kaplan–Meier survival curves [6]. A multivariate forward stepwise Cox proportional hazards regression analysis was undertaken to identify independent predictors for 1-year mortality [7]. All the variables listed in Tables 1–3 were offered as potential risk factors, including the timing of IABP support. The final risk model was used to risk adjust the Kaplan–Meier survival curves. All statistical analysis was performed retrospectively with SAS for Windows Version 8.2.


   3. Results
Top
 Abstract
 1. Introduction
 2. Methods
 3. Results
4. Discussion
 References
 
3.1. Patient characteristics
Vast difference in case-mix existed between the five study groups (Tables 1–3). When compared to patients who did not require IABP support, the patients who did require IABP support were more likely to be older, to have severe angina, to have poor ventricular function (ejection fraction <30%), to have had a previous myocardial infarction, to have preoperative renal dysfunction or to have had an emergent procedure.

The numerous differences that existed between the groups is best illustrated by the Additive EuroSCORE (Table 1). The two preoperative IABP support groups (Groups B and C) had significantly higher estimated risk than those not requiring support (Group A). Those patients who required intra- and post-operative IABP support (Groups D and E) also had significantly higher estimated risk than those not requiring support. This preoperative risk was not as high as for those in Group B or C.

3.2. Indications for IABP support
The indications for IABP support are shown in Table 4. All but one patient in Group C had coronary artery bypass grafts performed and 12 patients had mitral valve replacement or repair. Fifteen patients had unstable angina. The other 10 patients had suffered from myocardial infarctions within the previous month and were haemodynamically unstable and thus required IABP support.


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  		Table 4. Indications for IABP use
 
In Group D 108 patients could not be weaned from the cardiopulmonary bypass pump without the aid of the IABP. The IABP was used to provide haemodynamic support during OPCAB surgery for the other 12 patients (all of these patients were alive at 1 year).

In Group E the IABP was inserted after post-operative low cardiac output did not improve with judicious fluid loading and inotropic support.

3.3. IABP complications
Major IABP-related complications occurred in seven patients (2.9%). Four of these patients were women, two patients had peripheral vascular disease and none were diabetic.

One patient required femoral artery repair and another required femoral embolectomy. Two patients developed limb ischemia that resolved when the IABP was removed. Two patients developed IABP insertion site infection that responded to antibiotics and one patient developed a false aneurysm of the femoral artery that resolved with conservative management.

There were also three cases in which the IABP developed a leak and no clinical complication resulted.

3.4. Survival
Four-hundred and fifty (5.8%) deaths occurred during the 1-year follow-up, this included 230 (3.0%) deaths that occurred within 30 days of surgery. The number of patients at risk of death at 1-year in Groups A, B, C, D, and E were 7112, 23, 15, 76, and 28, respectively. Freedom from death at 30-days and 1-year for Groups A–E are shown in Fig. 1. Patients who received IABP support at any time were more likely to die within the first 30 days. Patients who received post-operative IABP support had the lowest 30-day survival at 55.4%.



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  		Fig. 1. Observed survival following cardiac surgery based on insertion of IABP.

 
Table 5 shows the independent risk factors for mortality at 1-year. Preoperative additive EuroSCORE, poor ejection fraction, triple-vessel disease and number of valves operated on had an effect, as did post-operative myocardial infarction, stroke and renal failure. After taking all of these factors into account, the requirements for intra- and post-operative IABP support were still identified as having an independent negative association with 1-year survival. Adjusted freedom from death at 30-days and 1-year for Groups A–E are shown in Fig. 2. When comparing group E with group D, we find that the hazard ratio for mortality was 1.8 (95% confidence intervals 1.2–2.7; P=0.002), indicating that patients with IABP insertion in the post-operative period had a significantly higher mortality at 1-year compared to patients given IABP support in the intra-operative period.


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  		Table 5. Independent risk factors for 1-year mortality
 


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  		Fig. 2. Adjusted survival following cardiac surgery by insertion of IABP (survival curves adjusted for factors listed in Table 5).

 

   4. Discussion
Top
 Abstract
 1. Introduction
 2. Methods
 3. Results
 4. Discussion
References
 
In this study we have shown that after risk-adjustment, there is a significant survival benefit at 1-year among patients in whom IABP support was commenced pre- or intra-operatively over those in whom IABP support was commenced during the post-operative period.

Other studies [8–10] have suggested this but not analysed the effect timing of IABP support had on patient survival. Patients who require post-operative IABP support are known to have high hospital mortality. However, these patients also have a higher adjusted mortality up to 1-year after the initial operation.

The relative benefits of pre-operative IABP support have only recently been quantified [11]. Cardiac surgery often results in some degree of temporary myocardial dysfunction and inotropes are used to provide temporary haemodynamic support. Escalating inotropic requirements usually preceed commencement of IABP support. In this series because of procedural complications during surgery, some haemodynamically stable patients were identified as having an increased risk of developing low cardiac output. Post-operative IABP support was commenced ‘prophylactically’ before escalating inotropic requirements. Alternately, an arterial line was inserted into the femoral artery to facilitate IABP insertion if it became necessary. These patients may have benefited from this early intervention, but the numbers were too small to analyse.

The risks of vascular injury with the IABP cannot be ignored [4,12–16] and opinions vary regarding the relative costs of escalating pharmacologic therapy or of using an IABP. These factors may affect the decision to use an IABP, but they have been minimised as a result of decreased IABP cost, improvements in IABP timing software (making them easier to use) and smaller catheter sizes. The smaller IABP catheter size may have also contributed to the lower incidence of vascular complications requiring surgical intervention in this series than in earlier series.

In our experience when haemodynamic instability occurs during OPCAB surgery, IABP support is preferred over the use of inotropes or cardiopulmonary bypass. Of interest is that all of the patients in whom the IABP was used to provide OPCAB support were free of serious complications and were alive at 1 year. This is a relatively recent trend [17] and suggests a greater acceptance of the IABP as a means of cardiac support with only a small associated risk.

Prophylactic IABP support in high-risk patients in this study resulted in 1-year survival that did not differ significantly from that of patients who did not require IABP support. This corroborates the evidence from Christenson [18] who showed that preoperative IABP insertion in high-risk cases reduced the cost of inpatient treatment, the length of stay in the intensive care and the in-hospital mortality. However, Holman et al. [19] used an adjusted case-matched model to show no survival benefit at 1-year in 550 high risk CABG patients with preincision IABP compared to controls matched using a propensity-score. Dunning and Prendergast reviewed the published evidence [20] and showed that there is evidence to support preoperative IABP insertion in patients with two of LVEF <30 or 40%, left main stem disease, unstable angina or redo-operation.

In Groups C–E some degree of cardiac insult occurred that caused haemodynamic compromise sufficiently great to require IABP support. The trend for a significant, but gradual decrease in the risk-adjusted survival at 1-year among the groups suggests that the cardiac insult suffered was sufficient enough to have a prolonged negative impact. Therefore, the requirement for mechanical haemodynamic support should be considered as a negative long-term prognostic indicator.

The observed 30-day mortality for all patients treated with an IABP was 34%. This is comparable to the 36–61% in other reported series [21]. In this series, major IABP-related complications only occurred in 2.9% of patients. This compared favourably with the morbidity reported in other series [12,13,22–24] that varied between 8 and 18%. The smaller catheters used in this series (8 and 9.5 French) could have been responsible for the apparent reduced complication rate. Recognised risks for IABP-related complications include female gender, peripheral vascular disease, older age and obesity [14,15]. None of these associations were found to be significant in this study.

However, although almost all insertions were percutaneous, a complete record of method of insertion (percutaneous or open surgical) was not kept. Method of insertion appears to have a significant effect on the complication rate [16], however, we cannot comment on this effect.

Arafa et al. [21] reported a 10-years series of cardiac surgery patients operated on during the 1980s in which IABP use was associated with an early mortality rate of 52.6% and the actual survival rates at 1, 5 and 10 years was 40, 32 and 22%, respectively. Both Benchmark registry [4,25] data and Baskett's review of IABP use in cardiac surgery [9] have demonstrated the evolution of the indications for IABP use. Whereas the conclusions that were made in these early studies were valid, patient selection and improvements in peri-operative management may influence the results in a more recent cohort of patients.

This is a retrospective analysis involving data collected prospectively and validated and is subject to the limitations of all such studies. Patients with a recognised high-risk (such as post-infarction ventricular septal defect repair) were not included. Selection bias is likely to have affected our results because the timing of insertion was based on clinical judgement and was not controlled by protocol. Controversy persists regarding the indications for IABP use [16]. It would be impossible to arrange a randomised trial involving intra- and post-operative IABP insertion mainly because of issues related to consent and sample size. This study, however, gives an accurate picture of current clinical practice.

Because patients with a high estimated pre-operative risk are more likely to require IABP support we attempted to analyse the effect timing of IABP support had on patients with good estimated pre-operative ventricular function. Unfortunately, the patient numbers were too small to allow adequate analysis. The 1-year study period was chosen in order to obtain complete follow-up. A longer study period may further highlight the differences identified.

In conclusion, patients who require unplanned peri-operative IABP support appear to have an increased mortality at 1-year. Therefore, earlier IABP support as part of surgical strategy would appear to be a strategy worth pursuing.


   Acknowledgments
 
We would like to acknowledge the co-operation given to us by the other Consultant Cardiac Surgeons at the Cardiothoracic Centre-Liverpool: Mr Drakeley, Ms Griffiths, Mr Page, Mr Pullan, Mr Rashid, Mr Weir. We would also like to thank Ms Deane for helping to ensure the completeness and accuracy of the data collected in our cardiac surgery registry.


   References
Top
 Abstract
 1. Introduction
 2. Methods
 3. Results
 4. Discussion
 References
 

  1. Warner CD, Weintraub WS, Craver JM, Jones EL, Gott JP, Guyton RA. Effect of cardiac surgery patient characteristics on patient outcomes from 1981 through 1995. Circulation 1997;96:1575-1579.[Abstract/Free Full Text]
  2. Wynne-Jones K, Jackson M, Grotte G, Bridgewater B. Limitations of the parsonnet score for measuring risk stratified mortality in the north west of England. The north west regional cardiac surgery audit steering group. Heart 2000;84:71-78.[Abstract/Free Full Text]
  3. Mangram AJ, Horan TC, Pearson ML, Silver LC, Jarvis WR. Guideline for prevention of surgical site infection, 1999. Centers for disease control and prevention (CDC) hospital infection control practices advisory committee. Am J Infect Control 1999;27:97-132(quiz 33–34; discussion 96).[CrossRef][Medline]
  4. Ferguson 3rd JJ, Cohen M, Freedman Jr RJ, Stone GW, Miller MF, Joseph DL, Ohman EM. The current practice of intra-aortic balloon counterpulsation: results from the benchmark registry. J Am Coll Cardiol 2001;38:1456-1462.[Abstract/Free Full Text]
  5. 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]
  6. Kaplan E, Meier P. Nonparametric estimation from incomplete observations. J Am Stat Assoc 1958:547-581.
  7. Cox D. Regression models and life tables. J R Stat Soc 1972;34:187-220.
  8. Meco M, Gramegna G, Yassini A, Bellisario A, Mazzaro E, Babbini M, Pediglieri A, Panisi P, Tarelli G, Frigiola A, Menicanti L, Cirri S. Mortality and morbidity from intra-aortic balloon pumps. Risk analysis. J Cardiovasc Surg (Torino) 2002;43:17-23.[Medline]
  9. Baskett RJ, Ghali WA, Maitland A, Hirsch GM. The intraaortic balloon pump in cardiac surgery. Ann Thorac Surg 2002;74:1276-1287.[Abstract/Free Full Text]
  10. Torchiana DF, Hirsch G, Buckley MJ, Hahn C, Allyn JW, Akins CW, Drake JF, Newell JB, Austen WG. Intraaortic balloon pumping for cardiac support: trends in practice and outcome, 1968 to 1995. J Thorac Cardiovasc Surg 1997;113:758-764(discussion 64–69).[Abstract/Free Full Text]
  11. Christenson JT, Simonet F, Schmuziger M. Economic impact of preoperative intraaortic balloon pump therapy in high-risk coronary patients. Ann Thorac Surg 2000;70:510-515.[Abstract/Free Full Text]
  12. Arafa OE, Pedersen TH, Svennevig JL, Fosse E, Geiran OR. Vascular complications of the intraaortic balloon pump in patients undergoing open heart operations: 15-year experience. Ann Thorac Surg 1999;67:645-651.[Abstract/Free Full Text]
  13. Meharwal ZS, Trehan N. Vascular complications of intra-aortic balloon insertion in patients undergoing coronary reavscularization: analysis of 911 cases. Eur J Cardiothorac Surg 2002;21:741-747.[Abstract/Free Full Text]
  14. Miller JS, Dodson TF, Salam AA, Smith 3rd RB. Vascular complications following intra-aortic balloon pump insertion. Am Surg 1992;58:232-238.[Medline]
  15. Naunheim KS, Swartz MT, Pennington DG, Fiore AC, McBride LR, Peigh PS, Barnett MG, Vaca KJ, Kaiser GC, Willman VL. Intraaortic balloon pumping in patients requiring cardiac operations. Risk analysis and long-term follow-up. J Thorac Cardiovasc Surg 1992;104:1654-1660(discussion 60–61).[Abstract]
  16. Christenson JT, Cohen M, Ferguson 3rd JJ, Freedman RJ, Miller MF, Ohman EM, Reddy RC, Stone GW, Urban PM. Trends in intraaortic balloon counterpulsation complications and outcomes in cardiac surgery. Ann Thorac Surg 2002;74:1086-1090(discussion 90–91).[Abstract/Free Full Text]
  17. Kim KB, Lim C, Ahn H, Yang JK. Intraaortic balloon pump therapy facilitates posterior vessel off-pump coronary artery bypass grafting in high-risk patients. Ann Thorac Surg 2001;71:1964-1968.[Abstract/Free Full Text]
  18. Christenson JT, Simonet F, Badel P, Schmuziger M. Evaluation of preoperative intra-aortic balloon pump support in high risk coronary patients. Eur J Cardiothorac Surg 1997;11:1097-1103(discussion 104).[Abstract]
  19. Holman WL, Li Q, Kiefe CI, McGiffin DC, Peterson ED, Allman RM, Nielsen VG, Pacifico AD. Prophylactic value of preincision intra-aortic balloon pump: analysis of a statewide experience. J Thorac Cardiovasc Surg 2000;120:1112-1119.[Abstract/Free Full Text]
  20. Dunning J, Prendergast B. Which patients would benefit from an intra-aortic balloon pump prior to cardiac surgery?. Interact Cardiovasc Thorac Surg 2003;2:416-419.[Abstract/Free Full Text]
  21. Arafa OE, Pedersen TH, Svennevig JL, Fosse E, Geiran OR. Intraaortic balloon pump in open heart operations: 10-year follow-up with risk analysis. Ann Thorac Surg 1998;65:741-747.[Abstract/Free Full Text]
  22. Christenson JT, Buswell L, Velebit V, Maurice J, Simonet F, Schmuziger M. The intraaortic balloon pump for postcardiotomy heart failure. Experience with 169 intraaortic balloon pumps. Thorac Cardiovasc Surg 1995;43:129-133.[Medline]
  23. Gol MK, Bayazit M, Emir M, Tasdemir O, Bayazit K. Vascular complications related to percutaneous insertion of intraaortic balloon pumps. Ann Thorac Surg 1994;58:1476-1480.[Abstract]
  24. Makhoul RG, Cole CW, McCann RL. Vascular complications of the intra-aortic balloon pump: an analysis of 436 patients. Am Surg 1993;59:564-568.[Medline]
  25. Cohen M, Urban P, Christenson JT, Joseph DL, Freedman Jr RJ, Miller MF, Ohman EM, Reddy RC, Stone GW, Ferguson 3rd JJ. Intra-aortic balloon counterpulsation in US and non-US centres: results of the benchmark registry. Eur Heart J 2003;24:1763-1770.[Abstract/Free Full Text]



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