Experience with revascularization procedures does ...

EDITORIAL

European Heart Journal (2010) 31, 1954–1957 doi:10.1093/eurheartj/ehq172

Experience with revascularization procedures does matter: low volume means worse outcome William Wijns 1 and Philippe H. Kolh 2* 1

Cardiovascular Center Aalst, Belgium; and 2Cardiovascular Surgery Department, University of Liege Hospital (CHU ULg), B 35 Sart Tilman, Lie`ge 4000, Belgium

Online publish-ahead-of-print 5 June 2010

In the past 30 years, a large number of studies predominantly performed in the USA have investigated the relationship between short-term outcomes and provider volume for a wide variety of medical conditions and procedures, in particular percutaneous coronary interventions (PCI) and coronary artery bypass grafting (CABG) surgery.1 – 3 With the use of adequate statistical methods, Post et al. 4 have performed a meta-analysis of 10 PCI studies, including 1 322 342 patients in 1746 hospitals, and of 10 CABG studies, including 1 754 777 patients in 2391 hospitals. They found that patients undergoing PCI or CABG in high-volume hospitals performing .600 cases per year exhibit significantly lower periprocedural mortality than those treated at lower volume hospitals. This meta-analysis raises several important questions. Does the volume–outcome relationship persist after adjusting for patient case mix? Does the association vary as a function of patient age and predicted risk? To what extent is this association affected by patient clustering at specific centres? How do site variance-related issues affect the association? Is the association between hospital volume and outcome influenced by individual physician volume? What are the potential health policy implications of using hospital volume as a quality indicator?

Impact of volume on outcome of CABG surgery With few exceptions,5,6 studies have indicated that hospitals and surgeons with higher volumes have lower mortality rates for CABG operations.7 – 10 The relative risk reduction for CABG-related mortality was 9% in the present meta-analysis and was shown to remain valid in the most recent studies. Results from 30 New York State centres noted a significant decrease in

operative mortality in high-volume compared with low-volume hospitals, a difference that was maintained after risk adjustment.8 Although this state-wide study was among the most complete analyses based on clinical data, only a small proportion (,3%) had their CABG performed at low-volume hospitals due to New York State restrictions. There appears to be a substantial relationship between the volume of activity of the individual surgeon and outcome.8,11 However, annual surgeon volume is only one measure of surgeon experience. The cumulative surgeon volume occurring over many years could be a more appropriate metric. Another open issue is whether annual surgeon volume is equally important in determining quality of care for surgeons with many years of experience vs. less experienced surgeons. Zacharias et al. 6 showed that, when the surgical team applies similar patient care standards and clinical pathways and emphasizes a team approach to cardiac surgery care, it is possible to achieve similar operative CABG outcomes at centres with low-volume or high-volume cardiac surgery programmes.

Impact of volume on PCI outcome The relative risk reduction for PCI-related mortality was 13% in the present meta-analysis and was not attenuated over time. The advent of coronary stents has reduced the incidence of PCI-related complications, including the risk of emergency CABG. As a result, procedural outcomes of elective procedures have been levelled out. In a Californian registry study carried out between 1984 and 1996, the disparity in outcomes between low- and high-volume centres narrowed, and complication rates improved in all hospitals.12 Therefore, for procedures with low short-term mortality such as PCI, additional outcome measures, including the need for same-day CABG surgery, same-stay CABG surgery, and readmission within a short period of time for complications related to the index admission, should be considered. In a population-based study, examining the data from New York’s PCI Reporting system in 1998–2000, Hannan et al. 11 showed that for hospital volumes ,400 and operator volumes ,75, the respective odds

The opinions expressed in this article are not necessarily those of the Editors of the European Heart Journal or of the European Society of Cardiology.

* Corresponding author. Tel: +32 4 366 7163, Fax: +32 4 221 31 58, Email: [email protected] †

doi:10.1093/eurheartj/ehq151

Published on behalf of the European Society of Cardiology. All rights reserved. & The Author 2010. For permissions please email: [email protected].

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This editorial refers to ‘The relation between volume and outcome of coronary interventions: a systematic review and meta-analysis’†, by P.N. Post et al., on page 1985

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Cross-talk between volumes of CABG and PCI procedures Programmes that perform a relatively large number of PCI procedures and a low volume of CABG procedures might tend to perform CABG procedures on a more complex patient population. Carey et al. 18 showed that a statistically significant effect of PCI volume on CABG mortality occurs in lower-volume hospitals when the PCI/CABG ratio exceeds 2.0. Compared with highvolume hospitals, low-volume hospitals tended to operate on patients at higher risk and under more emergent conditions. Reasons for those differences may include adverse selection, variance in clinical coding among hospitals, and differential threshold for surgery due to altered cluster experience and/or institutional financial pressure. More straightforward cases are referred for PCI, and patients with characteristics not defined in risk models, such as poor vessel quality or diffuse disease, tend to be referred for surgery.

Association or causal relationship? The literature distinguishes between two hypotheses as the potential explanations for the inverse volume–outcome relationship. The first is that ‘practice makes perfect’. The assumption is that a greater volume of patients should allow the ‘operative’ team to develop greater skills and judgement in the management of complex clinical conditions and therefore achieve better outcomes. The second is called ‘selective referral patterns’: ‘operating’

teams with superior outcomes attract a greater number of patients. These hypotheses have different policy implications. Under the first hypothesis, and in an environment where cost containment is important, centralization in the least costly institution would be a reasonable strategy; institutions would logically improve outcome with further experience and accomplish this at a lower cost. If the second hypothesis holds, then this strategy would not be reasonable, and centralization should be in those institutions with better outcomes. Both hypotheses are not mutually exclusive, as a more accomplished team will enjoy selective referral and demonstrate a greater improvement in outcomes as a result of the larger practice than would a less accomplished team.

Policy decisions In the past few years, there have been advocates in several countries for changing the landscape of health care delivery based on what is known about volume–outcome relationship. It was reasoned that a significant number of procedure-related deaths may be avoided if a policy of ‘regionalization’ was adopted to avoid low-volume hospitals. Such procedure volumedriven policy guidelines may have a number of drawbacks: lowvolume hospitals with good outcomes are handled in the same way as those with poor quality of care, similarly higher quality of care is assumed at all high-volume hospitals, and decisions do not account for potentially substantial physician–volume confounding effects. Enforcing a strict regionalization policy may cause significant disruption in the process of care delivery, with thousands of patients being referred away from low-volume to high-volume hospitals. Therefore, it has been recommended that such referrals be limited to high-risk patients. Risk of revascularization procedures can be estimated from a number of risk scores, of which the EuroSCORE for estimation of CABG-associated risk appears very robust.19 High-risk PCI procedures pertain both to the acute clinical presentations, i.e. cardiogenic shock, emergency or primary PCI cases, and to a number of anatomic subsets, among which are PCI of unprotected distal left main, chronic total occlusions, and complex multivessel disease.

Volume as a surrogate for quality Using hospital procedural volume as a quality indicator is attractive and widely accepted. This structural characteristic is readily available from administrative data, requires no complex adjustment techniques, is easily interpretable by the public, and is consistent with the common belief that ‘practice makes perfect’. Establishing a sound link with outcome requires, however, the availability of detailed clinical data as well as appropriate risk adjustment. Collection of clinical data sets for the purpose of public reporting has raised concerns about upcoding of risk factors, avoidance of performing interventions on high-risk patients, or lowering of indication thresholds in order to inflate procedural volumes. At the same time, it was shown that programmes introduced in New York and other US states have been associated with reductions in procedural deaths, in part because monitoring of comparative outcomes encourages quality improvement efforts.

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of mortality, same-day CABG surgery, and same-stay CABG surgery were 5.9, 4.0, and 3.9 times the odds for hospital volumes of ≥400 and operator volumes of ≥75. The volume –outcome relationship appears even more meaningful for high-risk and emergency PCI. Vakili et al. 13 reported on the global experience across an entire US state, including rural and urban, teaching and non-teaching, not-for-profit and for-profit hospitals. The average mortality rate for patients treated with primary PCI for acute myocardial infarction (AMI) was 5-fold higher than in patients undergoing elective PCI. The AMI patient is more often experiencing active ischaemia, manifested by chest pain, arrhythmias, and haemodynamic instability. High-volume centres tended to administer life-saving reperfusion therapies faster than lowvolume centres. The difference was larger for patients who underwent primary PCI than for those who received fibrinolytic therapy.14 Similar findings were reported in two recent studies from Europe. Spaulding et al. 15 found a strong inverse relationship between hospital PCI volume and in-hospital mortality after emergency procedures. Zahn et al.,16 reporting on behalf of the ALKK registry, have demonstrated, in a study not included in the present meta-analysis, a significant inverse relationship between hospital mortality (from 4.41 to 2.78%, P ¼ 0.004) and quartiles of PCI volume. Similar findings were reported from the multicentric German Cypher registry.17 Therefore, tolerance of lowvolume thresholds for angioplasty centres with the purpose of providing primary PCI should not be recommended, even in underserved areas.

1956 Peterson et al. 9 concluded that hospital procedural volumes are best considered as a surrogate metric for quality in a setting where other more direct process and outcome assessments are not available. It seems reasonable to support the continued growth of national clinical databases, which are capable not only of tracking risk-adjusted care patterns and outcomes, but also of improving them.

Recent cross-sectional analysis of Medicare claims

Conclusions Data collection and reporting mechanisms are important and therefore they should be accurate and timely. The focus on shortterm mortality should be extended to long-term outcomes and patient’s symptoms, as reflected by their functional status and quality of life, particularly in light of the growing emphasis on the appropriate use of procedures. We need to understand better how the information is used by physicians, hospitals, the public, purchasers, payers, and referring doctors. Compliance with guidelines on hospital volumes should be strongly encouraged by national and international cardiology and cardiac surgery societies, and their implementation monitored by local regulatory boards. While the availability and accuracy of clinical quality metrics are constantly improved, it is appropriate to rely on procedural volumes, given the indisputable evidence that low volume means worse outcome. For example, the Leapfrog group recommends contracting with hospitals having annual volumes of at least 400 procedures a year for PCI, and .450 for CABG. Among other national or international agencies, the American College of

Cardiology and the American Heart Association both recommend that PCI be performed by experienced operators in high-volume hospitals, namely .400 PCI procedures per year per hospital and at least 75 procedures per year for operators.21 Conflict of interest: none declared.

References 1. Dudley RA, Johansen KL, Brand R, Rennie DJ, Milstein A. Selective referral to high-volume hospitals: estimating potentially avoidable deaths. JAMA 2000;283: 1159 –1166. 2. Halm EA, Lee C, Chassin MR. Is volume related to outcome in health care? A systematic review and methodologic critique of the literature. Ann Intern Med 2002; 137:511 – 520. 3. Luft HS, Bunker JP, Enthoven AC. Should operations be regionalized? The empirical relation between surgical volume and mortality. N Engl J Med 1979;301: 1364 –1369. 4. Post P, Kuijpers M, Ebels T, Zijlstra F. The relation between volume and outcome of coronary interventions: a systematic review and meta-analysis. Eur Heart J 2010; 31:1985 –1992. First published on 28 May 2010. doi:10.1093/eurheartj/ehq151. 5. Sollano JA, Gelijns AC, Moskowitz AJ, Heitjan DF, Cullinane S, Saha T, Chen JM, Roohan PJ, Reemtsma K, Shields EP. Volume –outcome relationships in cardiovascular operations: New York State, 1990 –1995. J Thorac Cardiovasc Surg 1999;117: 419 –428. 6. Zacharias A, Schwann TA, Riordan CJ, Durham SJ, Shah A, Papadimos TJ, Engoren M, Habib RH. Is hospital procedure volume a reliable marker of quality for coronary artery bypass surgery? A comparison of risk and propensity adjusted operative and midterm outcomes. Ann Thorac Surg 2005;79:1961 – 1969. 7. Birkmeyer JD, Siewers AE, Finlayson EV, Stukel TA, Lucas FL, Batista I, Welch HG, Wennberg DE. Hospital volume and surgical mortality in the United States. N Engl J Med 2002;346:1128 –1137. 8. Hannan EL, Wu C, Ryan TJ, Bennett E, Culliford AT, Gold JP, Hartman A, Isom OW, Jones RH, McNeil B, Rose EA, Subramanian VA. Do hospitals and surgeons with higher coronary artery bypass graft surgery volumes still have lower risk-adjusted mortality rates? Circulation 2003;108:795–801. 9. Peterson ED, Coombs LP, DeLong ER, Haan CK, Ferguson TB. Procedural volume as a marker of quality for CABG surgery. JAMA 2004;291:195 –201. 10. Wu C, Hannan EL, Ryan TJ, Bennett E, Culliford AT, Gold JP, Isom OW, Jones RH, McNeil B, Rose EA, Subramanian VA. Is the impact of hospital and surgeon volumes on the in-hospital mortality rate for coronary artery bypass graft surgery limited to patients at high risk? Circulation 2004;110:784 –789. 11. Hannan EL, Wu C, Walford G, King SB III, Holmes DR Jr, Ambrose JA, Sharma S, Katz S, Clark LT, Jones RH. Volume– outcome relationships for percutaneous coronary interventions in the stent era. Circulation 2005;112:1171 –1179. 12. Ho V. Evolution of the volume–outcome relation for hospitals performing coronary angioplasty. Circulation 2000;101:1806 –1811. 13. Vakili BA, Kaplan R, Brown DL. Volume–outcome relation for physicians and hospitals performing angioplasty for acute myocardial infarction in New York state. Circulation 2001;104:2171 –2176. 14. Canto JG, Every NR, Magid DJ, Rogers WJ, Malmgren JA, Frederick PD, French WJ, Tiefenbrunn AJ, Misra VK, Kiefe CI, Barron HV. The volume of primary angioplasty procedures and survival after acute myocardial infarction. National Registry of Myocardial Infarction 2 Investigators. N Engl J Med 2000; 342:1573 –1580. 15. Spaulding C, Morice MC, Lancelin B, El Haddad S, Lepage E, Bataille S, Tresca JP, Mouranche X, Fosse S, Monchi M, de Vernejoul N. Is the volume–outcome relation still an issue in the era of PCI with systematic stenting? Results of the greater Paris area PCI registry. Eur Heart J 2006;27:1054 – 1060. 16. Zahn R, Gottwik M, Hochadel M, Senges J, Zeymer U, Vogt A, Meinertz T, Dietz R, Hauptmann KE, Grube E, Kerber S, Sechtem U. Volume –outcome relation for contemporary percutaneous coronary interventions (PCI) in daily clinical practice: is it limited to high-risk patients? Results from the Registry of Percutaneous Coronary Interventions of the Arbeitsgemeinschaft Leitende Kardiologische Krankenhausarzte (ALKK). Heart 2008;94:329 –335. 17. Khattab AA, Hamm CW, Senges J, Toelg R, Geist V, Bonzel T, Kelm M, Levenson B, Nienaber CA, Pfannebecker T, Sabin G, Schneider S, Tebbe U, Neumann FJ, Richardt G. Sirolimus-eluting stent treatment at high-volume centers confers lower mortality at 6-month follow-up: results from the prospective multicenter German Cypher Registry. Circulation 2009;120:600 –606. 18. Carey JS, Danielsen B, Gold JP, Rossiter SJ. Procedure rates and outcomes of coronary revascularization procedures in California and New York. J Thorac Cardiovasc Surg 2005;129:1276 –1282.

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Ross et al. 20 recently investigated the potential relationship between hospital volume and 30-day mortality for three common medical conditions, based on nearly 3.5 million hospitalization records. They found that Medicare beneficiaries who were hospitalized between 2004 and 2006 in acute care hospitals in the USA for AMI, heart failure, or pneumonia had a decrease in the rate of death if they were admitted to a hospital that handled a large condition-specific volume of patients every year.20 However, the relationship between volume and decreased mortality was attenuated at greater volumes, and there was a threshold for each condition above which an increase in hospital volume was no longer associated with lower mortality. Moreover, once the annual volume reached 100 cases, the curve representing the association between volume and risk-adjusted mortality began to flatten, suggesting that the benefit of an increased volume of patients at a hospital would be most pronounced at low-volume hospitals and would be attenuated as the hospital’s volume increased. Given the complexity of factors that contribute to patient outcome after revascularization procedures, this recent study is consistent with previous evidence that the best performance is obtained through an optimal interaction between human and material resources, experience and routine, process and process management, case-mix and volume load.

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19. Roques F, Nashef SA, Michel P, Gauducheau E, de VC, Baudet E, Cortina J, David M, Faichney A, Gabrielle F, Gams E, Harjula A, Jones MT, Pintor PP, Salamon R, Thulin L. Risk factors and outcome in European cardiac surgery: analysis of the EuroSCORE multinational database of 19030 patients. Eur J Cardiothorac Surg 1999;15:816–822. 20. Ross JS, Normand SL, Wang Y, Ko DT, Chen J, Drye EE, Keenan PS, Lichtman JH, Bueno H, Schreiner GC, Krumholz HM. Hospital volume and 30-day mortality for three common medical conditions. N Engl J Med 2010;362:1110 –1118.

21. Smith SC Jr, Feldman TE, Hirshfeld JW Jr., Jacobs AK, Kern MJ, King SB III, Morrison DA, O’Neil WW, Schaff HV, Whitlow PL, Williams DO, Antman EM, Adams CD, Anderson JL, Faxon DP, Fuster V, Halperin JL, Hiratzka LF, Hunt SA, Nishimura R, Ornato JP, Page RL, Riegel B. ACC/AHA/SCAI 2005 guideline update for percutaneous coronary intervention: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/SCAI Writing Committee to Update 2001 Guidelines for Percutaneous Coronary Intervention). Circulation 2006;113: e166 – e286.

doi:10.1093/eurheartj/ehq147 Online publish-ahead-of-print 21 May 2010

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Hepatocellular carcinoma presenting as right heart failure Vikrant Nayar , Bhavana Singh , and Peter J. Pugh * Department of Cardiology, Addenbrooke’s Hospital, Hills Road, Cambridge CB2 0QQ, UK

* Corresponding author. Tel: +44 1223 349148, Fax: +44 1223 349149, Email: [email protected]

A 59-year-old Afro-Caribbean woman with a history of tuberculosis, hepatitis C, and excessive alcohol consumption presented to our institution for investigation of her breathlessness, worsening peripheral oedema, acute renal failure, and deranged liver function tests. She had elevated jugular venous pressure, hepatomegaly, gross peripheral oedema, ascites, and signs of chronic liver disease. Despite diuretic therapy and oral fluid restriction, her oedema persisted. Echocardiography demonstrated normal biventricular size and function with no valve pathology. In addition, a large homogeneous mass was seen in the right atrium (Panel A), with finger-like projections extending into the right ventricle during atrial systole and caudal extension into the inferior vena cava (Panel B). She had neither a central venous catheter nor other obvious prothrombotic cause for atrial thrombus formation. It was initially proposed that the mass was most likely atrial myxoma in an unusual position. Ultrasound of the liver, however, demonstrated several nodules consistent with malignancy (Panel C). Computed tomography demonstrated the typical appearance of hepatocellular carcinoma, with associated thrombus, extending from the right lobe of the liver into the hepatic vein and inferior vena cava and into the right atrium (Panel D). Multiple pulmonary nodules, in keeping with pulmonary metastases, and bilateral pulmonary emboli were also seen. She remained unresponsive to diuretic therapy and was discharged home for palliative care. (Panel A) Echocardiogram (apical four-chamber view) showing a large mass in the right atrium with finger-like projections into the right ventricle. (Panel B) Echocardiogram (subcostal view) appearing to show the right atrial mass extending caudally into inferior vena cava. (Panel C) Ultrasound showing multiple nodules within the right lobe of the liver. (Panel D) Contrast-enhanced computed tomogram demonstrating tumour in the right lobe of the liver and in the right atrium.

Published on behalf of the European Society of Cardiology. All rights reserved. & The Author 2010. For permissions please email: [email protected].

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CARDIOVASCULAR FLASHLIGHT