Percutaneous coronary intervention outcomes in patients treated by the public and private healthcare systems

Abstracts

INTRODUÇÃO: Os principais sistemas de custeio da saúde no Brasil, o Sistema Único de Saúde (SUS) e a saúde suplementar (SS), têm características peculiares e abrangem a quase totalidade dos pacientes encaminhados para intervenção coronária percutânea (ICP). Buscamos saber as diferenças populacionais e os resultados hospitalares da ICP entre os pacientes desses dois sistemas. MÉTODOS: No período de agosto de 2006 a novembro de 2010, 4.957 pacientes consecutivos foram submetidos a ICP, 2.802 (56,5%) pertencentes ao SUS e 2.155 à SS. RESULTADOS: Pacientes do SUS eram mais jovens, com menor grau de escolaridade, maior ocorrência de tabagismo, infarto do miocárdio (IM) prévio, lesões em um único vaso, disfunção ventricular esquerda, e utilização da técnica de stent direto. No grupo SS ocorreram mais diabetes, dislipidemia, revascularizações percutânea e cirúrgica prévias, acidente vascular cerebral prévio, insuficiência renal crônica, síndromes coronárias agudas, com e sem supradesnivelamento do segmento ST, lesões reestenóticas, lesões longas, ICPs primárias, e uso de inibidores da glicoproteína IIb/IIIa e de stents farmacológicos. Sucesso da ICP (96% vs. 96,1%; P = 0,87), IM (1,7% vs. 1,8%; P = 0,72), cirurgia de revascularização (0,1% vs. 0,2%; P = 0,85), acidente vascular cerebral (0,1% vs. 0,1%; P > 0,99) e óbito (1% vs. 1,2%; P = 0,48) hospitalares não diferiram entre os grupos. CONCLUSÕES: Os pacientes da SS apresentaram-se com maior complexidade clínica e angiográfica que os do SUS. No entanto, essas diferenças não alteraram o sucesso do procedimento e os eventos cardiovasculares e cerebrovasculares adversos maiores hospitalares.

Angioplastia; Stents; Sistema Único de Saúde; Saúde suplementar

ORIGINAL ARTICLE

^ITrainee Physician at the Hemodynamics and Interventionist Cardiology Service of Hospital Bandeirantes, São Paulo, Brazil

^IIDoctor. Interventionist Cardiologist Physician and Coordinator of the Hemodynamics and Interventionist Cardiology Service of Hospital Bandeirantes, São Paulo, SP, Brazil

^IIIMaster. Interventionist Cardiologist Physician and coordinator of the Hemodynamics and Interventionist Cardiology Service of Hospital Bandeirantes, São Paulo, SP, Brazil

^IVMaster. Interventionist Cardiologist Physician and Assistant at the Hemodynamics and Interventionist Cardiology Service of Hospital Bandeirantes, São Paulo, SP, Brazil

^VMaster. Interventionist Cardiologist Physician and Assistant at the Hemodynamics and Interventionist Cardiology Service of Hospital Bandeirantes, São Paulo, SP, Brazil

^VIInterventionist Cardiologist Physician and Assistant at the Hemodynamics and Interventionist Cardiology Service of Hospital Bandeirantes, São Paulo, SP, Brazil

^VIIMaster. Interventionist Cardiologist Physician and Assistant at the Hemodynamics and Interventionist Cardiology Service of Hospital Bandeirantes, São Paulo, SP, Brazil

^VIIITrainee Physician at the Hemodynamics and Interventionist Cardiology Service of Hospital Bandeirantes, São Paulo, Brazil

^IXTrainee Cardiologist Physician at Hemodynamics and Interventionist Cardiology Service of Hospital Bandeirantes, São Paulo, Brazil

^XTrainee Physician at the Hemodynamics and Interventionist Cardiology Service of Hospital Bandeirantes, São Paulo, Brazil

^XIInterventionist Cardiologist Physician and Assistant at the Hemodynamics and Interventionist Cardiology Service of Hospital Bandeirantes, São Paulo, SP, Brazil

^XIIInterventionist Cardiologist Physician and Assistant at the Hemodynamics and Interventionist Cardiology Service of Hospital Bandeirantes, São Paulo, SP, Brazil

^XIIIInterventionist Cardiologist Physician and Assistant at the Hemodynamics and Interventionist Cardiology Service of Hospital Bandeirantes, São Paulo, SP, Brazil

Correspondence to

ABSTRACT

BACKGROUND: The main healthcare funding systems in Brazil, the public and the private healthcare systems (PuHS and PrHS, respectively), have peculiar characteristics and cover almost all patients referred for percutaneous coronary intervention (PCI). Our objective was to identify population differences and PCI hospital outcomes in patients using both systems.

METHODS: From August 2006 to November 2010, 4,957 consecutive patients were submitted to PCI, 2,802 (56.5%) were from the PuHS and 2,155 from the PrHS.

RESULTS: Patients from the PuHS were younger, had less education, greater incidence of smoking, prior myocardial infarction (MI), single-vessel disease, left ventricular dysfunction, and received more direct stenting. In the PrHS group, there was more diabetes, dyslipidemia, prior coronary bypass graft surgery (CABG) and PCI, prior stroke, chronic renal failure, ST-segment elevation and non-ST segment elevation acute coronary syndromes, restenotic lesions, long lesions, primary PCIs, use of glycoprotein IIb/IIIa inhibitors and drug-eluting stents. PCI success (96% vs. 96,1%; P = 0.87), MI (1.7% vs. 1.8%; P = 0.72), CABG (0.1% vs. 0.2%; P = 0.85), stroke (0.1% vs. 0.1%; P > 0.99) and death (1% vs. 1.2%; P = 0.48) were not different between groups.

CONCLUSIONS: Patients from the PrHS had greater clinical and angiographic complexity than those from the PuHS. However, these differences did not affect the success of the procedure and the rate of in-hospital major adverse cardiovascular and cerebrovascular events.

Descriptors: Angioplasty. Stents. Unified Health System. Supplemental health.

Coronary artery disease is a major cause of morbidity and mortality in Brazil, and is responsible for high costs in both the Unified Health System (Sistema Único de Saúde - SUS), which relies on public funding, as well as the supplemental health (SH) system, which utilizes private funding. In 2010, 55,754 percutaneous coronary interventions (PCIs) were performed in SUS patients, which cost over R$ 85 million.¹

These two healthcare systems have specific characteristics and cover almost all patients referred for PCI. The public health system, SUS, in spite of its concept of universality, does not make drug-eluting stents available, the device of choice in PCIs performed in developed countries. SUS also limits the use of stents to, at most, two devices per procedure, which makes the percutaneous treatment of coronary artery disease more complex, generating staged interventions or referrals for coronary artery bypass graft (CABG) surgery, which are associated with higher costs.² The SH system does not have these limitations; however, there is an increasing demand from health plan agencies for medical justifications for the interventions and for the materials needed.

The aim of this study was to assess the impact of these differences on the in-hospital PCI outcomes in an institution that provides care to patients who belong to either of the two healthcare systems available in Brazil.

METHODS

Patients

From August 2006 to November 2010, 4,957 consecutive patients underwent PCI at the Interventional Cardiology Department at the Hospital Bandeirantes (São Paulo, SP). Among these, 2,802 (56.5%) were SUS patients and 2,155 were SH patients, constituting the two groups compared in this study. Clinical, angiographic and procedural characteristics were compared, as well as the success rates and incidence of adverse events until hospital discharge.

The data were prospectively collected and stored in a computer database for future analysis.

Percutaneous coronary intervention

The PCIs were performed almost entirely through the femoral access route; radial or brachial approaches were used in a few cases. The choice of material and technique during the procedure were at the surgeon's discretion. Unfractionated heparin was used at the start of the procedure at a dose of 70 U/kg to 100 U/kg, except in patients who were already using low molecular-weight heparin during the 12 hours prior to the surgery. In these cases, an additional dose of 0.3 mg/kg of enoxaparin was administered intravenously during the - eight to 12 hours prior to the surgery. All patients received combined antiplatelet therapy with acetylsalicylic acid (100-200 mg/ day) and clopidogrel (loading dose of 300-600 mg and maintenance dose of 75 mg/day).

Angiographic analysis and definitions

Analyses were performed using at least two orthogonal projections by experienced surgeons using quantitative digital angiography. This study used the same angiographic criteria as the National Cardiovascular Intervention Centre (Central Nacional de Intervenções Cardiovasculares - CENIC) of the Brazilian Society of Interventional Cardiology.³ Long lesions were defined as those with lengths > 20 mm. The Thrombolysis in Myocardial Infarction (TIMI) score was used to classify the pre- and post-procedural coronary flow.⁴ Procedural success was defined as the achievement of angiographic success (residual stenosis < 30% with TIMI flow 3) and the absence of major adverse cardiovascular, and cerebrovascular events, i.e., death from any cause, myocardial infarction (MI), stroke, and emergency CABG surgery.⁵ Post-PCI myocardial infarction was defined by the presence of new ischaemic electrocardiogram alterations, > three-fold upregulation of laboratory markers compared to the upper normal value, and/or angiographic evidence of target vessel occlusion. Emergency CABG surgery was considered when it was performed immediately after the PCI.

Statistical Analysis

The data stored in an Oracle database were plotted in Excel spreadsheets and analyzed with SPSS software, version 15.0. Continuous variables were expressed as vs. 18.3%; P < 0.01) and previous incidence of mi means and standard deviations, and categorical varia-(19.6% vs. 16%; p < 0.01). the hs group had more bles were expressed as absolute numbers and percen-incidence of (27.5% vs. 31.6%; p < 0.01), dyslipidemia tages. Associations between continuous variables were (28% vs. 40.7%; P < 0.01), CABG (6.7% vs. 17.1%; evaluated by Student's t-test or the Mann-Whitney test. P < 0.01), previous pci (14.7% vs. 19.9%; p < 0.01), Associations between categorical variables were eva-previous stroke (2% vs. 3.2%; P = 0.01), chronic renal luated using the chi-squared or Fisher's exact test, using failure (2.3% vs. 3.2%; P = 0.04), and acute coronary 2×2 tables. For larger tables, the chi-squared test or the syndromes, with and without ST-segment elevation, as likelihood ratio (G) was applied. A significance level the initial clinical presentation (Table 1). of P < 0.05 was used for all analyses.

RESULTS

The SUS group was three years younger (60.6 ± 11.3 years vs. 64 ± 12.4 years; P < 0.01), had a lower degree of education, higher incidence of smoking (26.8% vs. 18.3%; P < 0.01) and previous incidence of MI (19.6% vs. 16%; P < 0.01). The HS group had more incidence of (27.5% vs. 31.6%; P < 0.01), dyslipidemia (28% vs. 40.7%; P < 0.01), CABG (6.7% vs. 17.1%; P < 0.01), previous PCI (14.7% vs. 19.9%; P < 0.01), previous stroke (2% vs. 3.2%; P = 0.01), chronic renal failure (2.3% vs. 3.2%; P = 0.04), and acute coronary syndromes, with and without ST-segment elevation, as the initial clinical presentation (Table 1).

Regarding angiographic characteristics (Table 2), the SUS group showed a higher frequency of patients with single-vessel disease (57.6% vs. 50.3%) and left ventricular dysfunction (23.9% vs. 17%; P < 0.01). The SH group had more patients with restenosis (2.4% vs. 4.9%; P < 0.01) and longer lesions (10.9% vs. 16.3%; P < 0.01). There were no differences in the pre-procedure TIMI flow, the type of vessel treated, and lesions with thrombi or bifurcations.

Regarding procedural characteristics (Table 3), there was a predominance of the use of the direct stenting technique (47.2% vs. 37.3%; P < 0.01). In the SH group, there was a higher occurrence of primary PCIs and the use of glycoprotein IIb/IIIa inhibitors (4.7% vs. 10.6%; P < 0.01). the use of des was unique to the sh group, representing 18.4% of the total number of stents used. the mean length of the stents was higher in the sh group (17.8 ± 6.7 mm vs. 19.2 + 7.2 mm; p < 0.01), with no differences regarding the diameter and quantification of obstructions pre- and post-procedure in the two groups.

The rates of PCI success (96% vs. 96.1%; P = 0.87), in-hospital MI (1.7% vs. 1.8%; P = 0.72), CABG (0.1% vs. 0.2%; P = 0.85), stroke (0.1% vs. 0.1%; P > 0.99), and death (1% vs. 1.2%; P = 0.48) did not differ between the two groups (Table 4).

DISCUSSION

In the present study, the differences between the two health systems, especially regarding universal and free access to SUS services, the limitation in the number of stents used per procedure, and the non-availability of DES resulted in differences in the composition of the two groups with regard to their demographic, clinical, angiographic, and procedural characteristics.

The SH group was three years older, a fact that may reflect better cardiovascular prevention and primary care in this population. Women, as well as diabetics, numbered approximately one-third of patients in both groups, figures that have been repeated in several registries.^3,6 In this study, smoking showed a similar incidence to that found in a Brazilian epidemiological study, which also showed a higher incidence in a population with lower levels of education.⁷ The rate of dyslipidemia was greater in SH group patients; however, the values were consistent with the average values found in the literature.⁸

The greater number of patients in the SH group with previous revascularization, either surgical or percutaneous, may be related to the difficulty of access to health services of high complexity among SUS patients. This difficulty can also explain the differences from the AMI treatment, in which there is a greater number of SH patients treated in the acute phase, resulting in a higher frequency of primary PCIs, and the use of glycoprotein IIb/IIIa. Conversely, the SUS group showed a higher number of PCIs performed at a later phase of AMI. In a recently published comparative analysis between SUS and SH patients with primary PCI data in the present hospital, there was a longer delay in the transference of SUS patients from the center of origin to the referral hospital.⁹

The greater clinical complexity of the SH group, which contained a higher number of diabetic patients, patients with previous revascularizations, and patients with chronic renal failure, reflected a greater angiographic complexity. Multivessel patients with longer and restenotic lesions were more frequent in this group. Patients with such clinical and angiographic complexities constitute the scenario where the use of DES has demonstrated its most significant benefits in terms of reducing restenosis and new interventions in relation to BMS.^10-13 In this hospital, the use of DES in approximately 20% of the patients (according to the Brazilian mean in the CENIC registry)³ mainly includes the most complex cases. The availability of DES only in the SH justifies the difference in clinical and angiographic complexity between the groups. The SUS rule that establishes the use of only two stents per procedure, which are necessarily BMS, limits the optimal application of PCI in patients with multivessel disease and diabetes. Consequently, this directs them to staged procedures or surgical revascularization, which may result in higher costs.

The lower angiographic complexity in the SUS group allowed the use of shorter stents and direct stenting techniques without pre-dilatation in almost half of the lesions treated. As the direct stenting technique has a high rate of failure in calcified, long lesions and in the presence of tortuosities, it has been used in less complex lesions.¹⁴

Procedural success, which was high in both groups, and clinical outcomes (death, stroke, MI, and urgent revascularization) were similar despite the distinct profiles. The possibility of using new technologies, including drug-eluting stents in SH, had a positive influence, providing in-hospital results similar to those of the group with less complex clinical and angiographic characteristics (SUS). The incorporation of DES by SUS would significantly broaden the benefits of PCI, especially for more complex patients for whom its clinical benefits are unquestionable.

Study limitations

There are certain limitations of the present study: the retrospective analysis of data from two cohorts with non-adjusted clinical variables, the fact that it was conducted in a single center, and the absence of late follow-up.

CONCLUSIONS

Patients in the SH group showed greater clinical and angiographic complexity than patients in the SUS group. However, these differences did not have an effect on procedural success and in-hospital major adverse cardiovascular and cerebrovascular events.

CONFLICT OF INTEREST

The authors declare no conflicts of interest.

REFERENCES

• 1. Brasil. Ministério da Saúde. DATASUS. Informações de saúde [Internet]. [citado 2012 out. 31]. Brasília; 2012. Disponível em: http://www2.datasus.gov.br/DATASUS/index.php?area=02
• 2. Pedroso AP, Meireles GCX, Abreu Filho LM, Forte AAC, Sumita MK, Favarato D, et al. Avaliação do custo do implante programado de múltiplos stents em mais de uma intervenção percutânea em pacientes com doença coronária multiarterial. Rev Bras Cardiol Invasiva. 2007;15(3):249-54.
• 3. Cardoso CO, Quadros AS, Mattos LA, Gottschall CA, Sarmento-Leite RE, Marin-Neto JA. Use of drug-eluting stents in Brazil: the CENIC (National Registry of Cardiovascular Interventions) Registry. Arq Bras Cardiol. 2007;89(6):322-6.
• 4. TIMI Study Group. The Thrombolysis in Myocardial Infarction (TIMI) trial. Phase I findings. N Engl J Med. 1985;312(14):932-6.
• 5. Mattos LA, Lemos Neto PA, Rassi Jr. A, Marin-Neto JA, Sousa AGMR, Devito FS, et al. Diretrizes da Sociedade Brasileira de Cardiologia - Intervenção Coronária Percutânea e Métodos Adjuntos Diagnósticos em Cardiologia Intervencionista (II Edição - 2008). Arq Bras Cardiol. 2008;91(6 Supl 1):1-58.
• 6. Narayan KMV, Boyle JP, Geiss LS, Saaddine JB, Thompson TJ. Impact of recent increase in incidence on future diabetes burden: U.S. 2005-2050. Diabetes Care. 2006;29(9):2114-6.
• 7. Brasil. Ministério da Saúde; Instituto Nacional do Câncer, Coordenação de Prevenção e Vigilância. Prevalência de tabagismo no Brasil: dados dos inquéritos epidemiológicos em capitais brasileiras. Brasília; 2004.
• 8. Sposito AC, Caramelli B, Fonseca FAH, Bertolami MC, Afiune Neto A, Souza AD, et al. Diretrizes da Sociedade Brasileira de Cardiologia - IV Diretriz Brasileira sobre Dislipidemias e Prevenção da Aterosclerose. Arq Bras Cardiol. 2007;88(Supl I):1-19.
• 9. Barreto R, Cantarelli MJC, Castello Jr. HJ, Gonçalves R, Gioppato S, Guimarães JBF, et al. Resultados da intervenção coronária percutânea primária em pacientes do Sistema Único de Saúde e Saúde Suplementar. Rev Bras Cardiol Invasiva. 2011;19(3):279-85.
• 10. Sousa AGMR, Costa Jr. JR, Moreira A, Costa RA, Cano MN, Andrade GAM, et al. Evolução clínica tardia dos stents farmacológicos: segurança e eficácia até cinco anos do Registro DESIRE. Rev Bras Cardiol Invasiva. 2007;15(3):221-7.
• 11. Tanajura LF, Feres F, Siqueira DA, Abizaid A, Fraulob SM, Fucci A, et al. Influência dos stents farmacológicos na seleção de pacientes diabéticos tratados por meio de intervenção coronária percutânea. Rev Bras Cardiol Invasiva. 2010;18(2):151-6.
• 12. Park DW, Seung KB, Kim YH, Lee JY, Kim WJ, Kang SJ, et al. Long-term safety and efficacy of stenting versus coronary artery bypass grafting for unprotected left main coronary artery disease: 5-year results from the MAIN-COMPARE (Revascularization for Unprotected Left Main Coronary Artery Stenosis: Comparison of Percutaneous Coronary Angioplasty Versus Surgical Revascularization) registry. J Am Coll Cardiol. 2010;56(2):117-24.
• 13. Holmes DR Jr, Cannon LA, Stahle E, Morice MC, Mack MJ, Feldman TE, et al. Four-year follow-up of the SYNTAX Trial: optimal revascularization strategy in patients with three-vessel disease and/or left main disease. TCT 2011: Transcatheter Cardiovascular Therapeutics 23^rd Annual Scientific Symposium, November 7-11, 2011, San Francisco, CA, USA.
• 14. Brito Jr. FS, Caixeta AM, Perin MA, Rati M, Arruda JA, Cantarelli M, et al. Comparison of direct stenting versus stenting with predilation for the treatment of selected coronary narrowings. Am J Cardiol. 2002;89(2):115-20.

Percutaneous coronary intervention outcomes in patients treated by public and private healthcare systems

Fabio Peixoto Ganassin^I; Marcelo José de Carvalho Cantarelli^II; Hélio José Castello Junior^III; Rosaly Gonçalves^IV; Silvio Gioppato^V; João Batista de Freitas Guimarães^VI; Evandro Karlo Pracchia Ribeiro^VII; Marcelo Mendes Farinazzo^VIII; Leonardo dos Santos Coelho^IX; Roberto Simões de Almeida^X; Julio Cesar Francisco Vardi^XI; Leonardo Cao Cambra de Almeida^XII; Patrícia Teixeira da Silva^XIII

Publication Dates

• Publication in this collection
  25 Feb 2013
• Date of issue
  Dec 2012

History

• Received
  17 Sept 2012
• Accepted
  28 Nov 2012