Comparative results of coronary intervention in patients with variant angina versus those with non-variant angina

Clinical outcome of coronary stenting in patients with variant angina refractory to medical treatment: a consecutive single-center analysis

OBJECTIVE

To investigate the efficacy of coronary stenting in patients with variant angina refractory to medical treatment.

SUBJECTS AND METHODS

Variant angina was diagnosed in 81 patients admitted to the Department of Cardiology between January 2003 and June 2011. However, coronary stenting was performed in 21 patients refractory to medical treatment, but coronary angiography and intravascular ultrasound were performed in all patients, and acetylcholine provocative test was performed in 11 of the 21 patients refractory to medical treatment. Coronary angiography was repeated after 9-12 months in the 21 patients with coronary stents. Clinical follow-up time was 2.5 ± 3.1 years (range 1-8).

RESULTS

Of the 81 patients, coronary angiography and intravascular ultrasound did not reveal significant stenosis in 13 (16.0%), but revealed 20-75% fixed stenosis in the remaining 68 (84.0%) patients. The acetylcholine provocative test was positive in the 11 patients. Of the 21 patients with coronary stents, the spasm site was located in the right coronary artery in 16 (76.2%) and in the left anterior descending artery in the remaining 5 (23.8%) patients. During the 1- to 8-year follow-up period, 1 of the 21 patients with stents developed recurrent episodes of variant angina, 5 patients had occasional chest pain, and the other 15 were asymptomatic. Coronary angiography at 9-12 months after initial evaluation demonstrated no stenosis in 3 patients, 20-40% in-stent mild intimal hyperplasia in 15 patients, and 50-80% in-stent restenosis in 3 patients. Coronary stenting was performed again in 2 patients.

CONCLUSIONS

The present study showed that coronary stenting for severe refractory coronary vasospasm was effective and without serious complications. It can be an alternative and viable option for some patients who are refractory to medical therapy and at a high risk of acute coronary syndrome recurrence.

Disruption of coronary vasomotor function: the coronary spasm syndrome

Abnormal coronary vasoconstriction, or coronary spasm, can be the result of several factors, including local and neuroendocrine aberrations. It can manifest clinically as a coronary syndrome and plays an important role in the genesis of myocardial ischemia. Over the past half century, coronary angiography allowed the in vivo demonstration of spasm in patients who fit the initial clinical description of the condition as reported by Prinzmetal et al. Several clinical, basic, and more recently, genetic studies have provided insight into the pathogenesis, manifestations, and therapy of this condition. It is not uncommonly encountered in patients with coronary syndromes and absence of clearly pathologic lesions on angiography. Provocation tests utilizing pharmacologic and nonpharmacologic stimuli combined with imaging (echocardiography or coronary angiography) can help make the correct diagnosis. The use of calcium channel blockers and long-acting nitrates is currently considered standard of care and the overall prognosis appears to be good. The recent discovery of genetic abnormalities predisposing to abnormal spasm of the coronaries has stimulated interest in the development of targeted therapies for the management of this condition.

Stent implantation in variant angina refractory to medical treatment

BACKGROUND

Vasospastic angina usually responds well to medical treatment.

HYPOTHESIS

The present study describes our experience in patients who received a coronary stent because of recurrent variant angina refractory to medical treatment and evaluates stent implantation as an alternative treatment.

MATERIALS AND METHODS

Between March 1998 and February 2005, recurrent variant angina was diagnosed in 22 patients admitted to our coronary care unit. Of these, five patients (22.7%), were refractory to pharmacologic treatment. Coronary angiography and coronary stents were indicated. Clinical follow-up was 29 +/- 6 months.

RESULTS

Stenting was performed during diagnostic coronary angiography in two patients. In the other three patients, the stent was implanted 24-48 h later. We observed coronary spasm recurrences proximal or distal to the stent in four patients-two during the stent implantation procedure and the other two in the coronary care unit within 48 h post angioplasty. Three patients where treated with additional stenting and the fourth patient improved with pharmacologic treatment. During follow-up three patients remained asymptomatic. The fourth patient had diffuse in-stent restenosis in the third month, and the fifth patient showed a de novo lesion in the treated segment 2 years later.

CONCLUSIONS

Stent implantation in patients with recurrent variant angina refractory to medical treatment may be an alternative treatment in carefully selected, clinically unstable patients. Spasm recurrences may occur in other segments of the treated artery, probably due to the diffuse nature of the disease. Immediate and continued surveillance is recommended because of the risk of adverse clinical events.

Coronary artery stent placement as a treatment of acute coronary syndrome in course of variant angina

High doses of calcium antagonists and nitrates are the treatment of choice in vasospasm angina when no stenosis or mild stenosis is present. In ca. 5-30% patients this kind of treatment is not effective. We present five cases of variant angina with acute coronary syndrome in patients despite standard pharmacological treatment. These patients also did not respond for intracoronary nitroglycerine injection. They were successfully treated with stent implantation in place of vasospasm. Our observations indicate that early enough interventional treatment prevent myocardial infarction. In one case in which stent placement was performed 12 h after clinical manifestation myocardial infarction with Q waves and enzymes release occurred. In others, accurately treated with stent implantation, coronary spasm did not produce myocardial damage. We did not see any clinical and biochemical evidence of myocardial infarction.

Is there a role for provocation testing to diagnose coronary artery spasm?

Spontaneous coronary artery spasm is an important cause of morbidity both in patients with coronary artery disease and in those with variant angina. A number of pharmacological agents have been identified which can provoke coronary artery spasm in susceptible patients. The role of provocation testing in the clinical diagnosis of coronary spasm is controversial. This is reflected by variations in the clinical use of provocation testing between specialist cardiac centres. Provocation testing appears to be a sensitive method of identifying patients with variant angina and active disease but such patients can often be diagnosed clinically. The specificity is less clear. There is little evidence that altering patient therapy on the basis of a positive test modifies prognosis. There may be a role for provocation testing in rare patients with refractory disease to identify a target site for coronary stenting. A more widespread use of these tests in patients with undiagnosed chest pain syndromes would not currently be recommended.