Does the coronary disease increase the hospital mortality in patients with aortic stenosis undergoing valve replacement?

Objectives: With the increase in life expectancy occurred in recent decades, it has been noted the concomitant increase in the prevalence of aortic stenosis and degenerative disease of atherosclerotic coronary artery. This study aims to evaluate the influence of atherosclerotic coronary artery disease in patients with critical aortic stenosis undergoing isolated or combined implant valve prosthesis and coronary artery bypass grafting. Methods: In the period of January 2001 to March 2006, there were analyzed 448 patients undergoing isolated implant aortic valve prosthesis (Group I) and 167 patients undergoing aortic valve prosthesis implant combined with coronary artery bypass grafting (Group II). Preand intraoperative variables elected for analysis were: age, gender, body mass index, stroke, diabetes mellitus, chronic obstructive pulmonary disease, rheumatic fever, hypertension, endocarditis, acute myocardial infarction, smoking, Fraction of the left ventricular ejection, critical atherosclerotic coronary artery disease, chronic atrial fibrillation, aortic valve operation prior (conservative), functional class of congestive heart failure, value serum creatinine, total cholesterol, size of the prosthesis used, length and number of distal anastomoses held in myocardial revascularization, duration of cardiopulmonary bypass and aortic clamping time. The statistical study employed invariant and multivariate analysis. Results: Hospital mortality was 14.3% (64 deaths) in Group I, and 14.5% (58 deaths) in patients with atherosclerotic coronary artery disease associated criticism (Group IB) and 12.8% (six deaths) in which had this association (Group IA). Hospital mortality in Group II was 17.6% (29 deaths), and 16.1% (20 deaths) in patients undergoing implantation of prosthetic aortic valve combined to complete myocardial revascularization (Group II) and 20.9% (nine deaths) in the myocardial revascularization with incomplete (Group IIB). Conclusions: In patients undergoing implant isolated from aortic valve prosthesis, the presence of atherosclerotic coronary artery disease associated critical in at least two arteries, influenced the hospital mortality. In patients undergoing surgical treatment combined the number of coronary arteries with critical atherosclerotic disease and extent of coronary artery bypass grafting (complete or incomplete), did not affect the hospital mortality, but the realization of more than three anastomoses in the distal myocardial revascularization interfered. Descriptors: Hospital mortality. Aortic valve stenosis. Heart valve prosthesis implantation. Work performed at Instituto do Coração Hospital das Clínicas, Faculdade de Medicina da Universidade de São Paulo (INCOR-HCFMUSP) São Paulo, SP, Brazil. Mailing address: José de Lima Oliveira Junior. Alameda Caiçara, 245 Alphaville Residencial 3 -Santana de Parnaíba São Paulo, SP, Brazil. ZIP: 06542-145 Article received on June 3rd, 2009 Article accepted on September 9th, 2009

OLIVEIRA JÚNIOR, JL ET AL -Does the coronary disease increase the hospital mortality in patients with aortic stenosis undergoing valve replacement?

METHODS
Perspective observational study (Coorte), involving two consecutive groups of patients, holders of AoS, associated or not to critical CAD, submitted to AVS, combined or not to RM, operated at the InCor-HC-FMUSP, between 2001 and 2006.Not including: patients submitted to any other combined surgical procedure; operated for acute endocarditis; holders of AoS associated to aortic insufficiency; submitted to any other previous heart surgery, other than the conservative surgical treatment of AoS; with more than one previous aortic valve operation; previous AVS, urgency or emergency.The patients were divided in two groups: • Group G1: holders of AoS submitted to isolated AVS, with associated CAD (G1A), without associated CAD (G1B); • Group G2 holders of AoS, associated to critical CAD, submitted to AVS combined to complete MR (G2A) or incomplete MR (G2B).
In the G1, the average age was 53.9 ±16.2 years, 47 (10.5%) patients presented critical associated CAD, 163 (36.4%) were female.In the GII, the average age was 67.3 ± 9.5 years, 42 (25.1%)were female.The frequency of preoperative and intra-operative data is described in Tables 1 and 2.

INTRODUCTION
For holders of aortic stenosis (AoS), the start of symptoms represents a critical point, by reducing life expectancy.In the 1950's, Kirklin et al. acquired unsatisfactory results with the surgical treatment of the aortic valve [1].In the following decades, the aortic valve substitution (AVS) became an efficient therapeutic alternative [2], achieving better results than those in drug or percutaneous treatments [3].The profile of the patients submitted to AVS has changed over the last few years, with an increase in the proportion of high risk patients [4,5].The surgical treatment combined of the coronary artery disease (CAD) + AoS represents about 15% of the cardiac operations currently performed in the United States [6].In the early 1990's, Lytle et al. [7], revising the operative results of the Cleveland Clinic Foundation, observed that the isolated surgical approach in the aortic valve had a negative impact in the operative mortality of patients holding valvar lesion combined to CAD.More recently, Florath et al. [8] reported a significant reduction in operative mortality of patients submitted to the combined procedure.
This study aims to evaluate the influence of CAD, in hospital mortality of patients holding AoS, submitted to AVS isolated or combined to myocardial revascularization (MR).For the statistical analysis in the group composition evaluation, the following tests were used: qui-square test, t of Student and exact test of Fisher, followed by multivariate analysis (logistical regression model).Admiting statistical significance level of P ≤ 0.05.The Hosmer-Lemeshow test was applied to test the model adjustment.The hospital deaths were considered routinely.

RESULTS
The patients submitted to isolated AVS (G1), the hospital mortality was 14.3%, being 57.8% due to cardiac causes and 42.2% due to non-cardiac causes.The distribution of hospital mortality of G1, according to perioperative data, is described in Tables 3 and 4. In G1B, the hospital mortality was 14.5%, in G1A, 12.8%, being 6.3% in patients with uniarterial disease, 33.3% in two arteries compromised, with no deaths in the three arteries compromised.In G1, serum creatinine e"1.5 mg/dL (P = 0.001), extracorporeal circulation time higher than 90 minutes (P = 0.022) and aortic clamping higher than 60 (P = 0.010), presence of associated CAD, in at least two arteries (P = 0.016) influenced hospital mortality (Table 5).
The patients submitted to AVS combined with MR (G2), the hospital mortality was 17.4%, being 10.4% in the one artery compromised, 13.6% in the two arteries compromised and 24.0% in the three arteries compromised.The distribution of hospital mortality in GII, according to perioperative data, is described in Tables 6 and 7.In G2A,   the hospital mortality was 16.1% and 20.9% in G2B.In G2, female (P = 0.037), extracorporeal circulation time higher than 180 minutes (P = 0.030), serum creatinine ≥ 1.5 mg/dL, cerebrovascular accident antecedent (P = 0.041) and performance of more than two distal anastomosis (P = 0.031) influenced hospital mortality (Table 8).

Table 2 .
Comparison of frequencies of preoperative and intraoperative data of G2A and G2B.

Table 3 .
Distribution of hospital mortality of G1, according to reoperative data.OLIVEIRA JÚNIOR, JL ET AL -Does the coronary disease increase the hospital mortality in patients with aortic stenosis undergoing valve replacement?

Table 4 .
Distribution of hospital mortality of G1, according to intraoperative data.G1: holders of AoS, associated or not with critical CAD, submitted to isolated AVS.N: number.OR: odds ratio (association measure).IC 95% : interval of confidence with confidence level of 95% of each association measure.p: probability of na event.Ao.Clamp.T..: aortic clamping time in minutes; ECC T.: extracorporeal circulation time in minutes.%: percentage

Table 5 .
Results of the logistic regression model of G1.G1: holders of AoS, associated or not with critical CAD, submitted to isolated AVS.N: number.OR: odds ratio (association measure).IC 95% : interval of confidence with confidence level of 95% of each association measure.p: probability of na event.CAD: critical CAD.Ao.Clamp.T..: aortic clamping time in minutes; ECC T.: extracorporeal circulation time in minutes.%: percentage OLIVEIRA JÚNIOR, JL ET AL -Does the coronary disease increase the hospital mortality in patients with aortic stenosis undergoing valve replacement?

Table 6 .
Distribution of hospital mortality of G2, according to preoperative data.
OLIVEIRA JÚNIOR, JL ET AL -Does the coronary disease increase the hospital mortality in patients with aortic stenosis undergoing valve replacement?

Table 8 .
Result of the logistic regression model of G2G2: holders of AoS, associated with critical CAD, submitted to AVS combined with MR.N: number.OR: odds ratio (association measure).IC 95 : interval of confidence with confidence level of 95% of each association measure.p: probability of an event.HBP: high blood pressure.ECC: extracorporeal circulation in minutes.CVA: cerebrovascular accident

Table 7 .
Distribution of hospital mortality of G2, according to intraoperative data.G2: holders of AoS, associated with critical CAD, submitted to AVS combined with MR.G2A: holders of AoS, associated with critical CAD, submitted to AVS combined with complete MR.G2B: holders of AoS, associated with critical CAD, submitted to AVS combined with incomplete MR.N: number.OR: odds ratio (association measure).IC 95 : interval of confidence with confidence level of 95% of each association measure.p: probability of an event.Ao.Clamp.T..: aortic clamping time in minutes; ECC T.: extracorporeal circulation time in minutes.MR: myocardial revascularization.anast: anastomoses.%: percentage JÚNIOR, JL ET AL -Does the coronary disease increase the hospital mortality in patients with aortic stenosis undergoing valve replacement?Rev Bras Cir Cardiovasc 2009; 24(4): 453-462 OLIVEIRA