Coronary angiography prior to surgery for valvular heart disease

Coronary angiography prior to surgery for valvular heart disease

Abstract: Coronary angiography prior to surgery for valvular heart disease is considered for those forty years and above if there are no coronary risk factors and for those thirty five years and above when there are coronary risk factors.

Screening coronary angiography is usual prior to surgery for valvular heart disease in older individuals even though most of these diagnostic angiograms turn out to be normal.  This is done because clinical, electrocardiographic, echocardiographic and radionuclide studies are not very specific for detection of coronary artery disease in the presence of severe valvular heart disease. Moreover, long term outcome is better if those with significant associated coronary artery disease undergo coronary artery bypass grafting in addition to valvular surgery.¹

Prevalence of coronary artery disease in valvular heart disease

Atalar E and colleagues in a retrospective analysis of over one thousand patients found about eleven percent prevalence of significant coronary artery disease in those undergoing surgery for rheumatic valvular disease.² They noted that those with associated coronary artery disease were older than those without coronary artery disease with a mean age of around 55 years vs 51 years. Conventional risk factors like hypertension, diabetes mellitus, dyslipidemia and smoking were seen in those with significant coronary artery disease. Among the valvular lesions, aortic stenosis was associated with coronary artery disease with an odds ratio of 1.66 while aortic regurgitation was inversely associated with an odds ratio of 0.56.

Similar eleven percent incidence of coronary artery disease in about two thousand two hundred patients with rheumatic heart disease was documented by Narang R and associates as well.³ They also noted that there is correlation between aortic stenosis and coronary artery disease and an inverse correlation between aortic regurgitation and coronary artery disease. These authors suggested a cut-off age of forty years in males and fifty five years in females for screening coronary angiography prior to surgery for valvular heart disease.

Multislice computerized tomographic (CT) coronary angiography

Multislice computerized tomographic coronary angiography has been shown to have a high negative predictive value for excluding significant coronary artery disease. Bettencourt N and colleagues evaluated around four hundred and fifty patients presurgical valvular heart disease patients prospectively and concluded that calcium screening is useful prior to CT coronary angiography to detect those likely to have positive and inconclusive results on CT angiography so that they can be directly referred to invasive coronary angiography.⁴ This approach would reduce the radiation risk as calcium screening carries lesser radiation risk than CT coronary angiography. Those deemed likely to have negative CT angiograms by calcium screening can proceed with CT coronary angiography as it is less invasive and still has a high negative predictive value.

References

1. Iung B, Drissi MF, Michel PL, de Pamphilis O, Tsezana R, Cormier B, Vahanian A, Acar J. Prognosis of valve replacement for aortic stenosis with or without coexisting coronary heart disease: a comparative study. J Heart Valve Dis. 1993; 2: 430-439.
2. Atalar E, Yorgun H, Canpolat U, Sunman H, Kepez A, Kocabaş U, Ozer N, Ovünç K, Aksöyek S, Ozmen F.  Prevalence of coronary artery disease before valvular surgery in patients with rheumatic valvular disease. Coron Artery Dis. 2012 Dec;23(8):533-7.
3. Narang R, Chadha DS, Goel K, Mishra S, Bajaj N, Sharma S, Gupta N, Bahl VK. Screening coronary angiography prior to surgery in rheumatic valvular heart disease: a study of 2,188 patients. J Heart Valve Dis. 2009 Jul;18(4):455-60.
4. Bettencourt N, Rocha J, Carvalho M, Leite D, Toschke AM, Melica B, Santos L, Rodrigues A, Gonçalves M, Braga P, Teixeira M, Simões L, Rajagopalan S, Gama V. Multislice computed tomography in the exclusion of coronary artery disease in patients with presurgical valve disease. Circ Cardiovasc Imaging. 2009 Jul;2(4):306-13.