Feasibility and safety of the transradial approach for the intracoronary spasm provocation test

Pharmacological coronary spasm provocative testing in clinical practice: A French Coronary Atheroma and Interventional Cardiology Group (GACI) position paper

Vasospastic angina, also described as Prinzmetal angina, was first described as a variant form of angina at rest with transient ST-segment elevation; it is common and present in many clinical scenarios, including chronic and acute coronary syndromes, sudden cardiac death, arrhythmia and syncope. However, vasospastic angina remains underdiagnosed, and provocative tests are rarely performed. The gold-standard diagnostic approach uses invasive coronary angiography to induce coronary spasm using ergonovine, methylergonovine or acetylcholine as provocative stimuli. The lack of uniform protocol decreases the use and performance of these tests, accounting for vasospastic angina underestimation. This position paper from the French Coronary Atheroma and Interventional Cardiology Group (GACI) aims to review the indications for provocative tests, the testing conditions, drug protocols and positivity criteria.

[Diagnosis and treatment of spastic angina revealed by cardiac arrest]

The prevalence of vasospastic angina is said to be low in Europe, but maybe because of a lack of diagnosis in the daily practice. However, coronary spasm is a common cause of cardiac arrest, especially among patients free of cardiac illness, and it should be systematically investigated after an unexplained cardiac arrest. Intracoronary spasm provocation test exposes patients to a lower risk compared to the risk of spontaneous spastic angina. Accurate modalities and diagnostic criteria have to be clarified for European population. Avoiding external causes of coronary spasm (such as cigarette smoking or more generally consuming coronary spasm inducing drugs) and prescribing antispastic medicine (first of all calcium channel blockers) are the basis of vasospastic angina treatment. However, recurrent coronary spasms have been reported despite an appropriate treatment and implantable automatic defibrillator has been implanted after case discussion when the onset of illness was cardiac arrest. We report the case of a patient recovering from cardiac arrest who had a positive spasm coronary provocation test, and was treated with calcium channel blockers and had been an automatic defibrillator implanted, with a coronary spasm provocation test performed afterward still contentious. While discussing this case, we are making a literature review of the diagnosis and treatment of spastic angina revealed by cardiac arrest.

[Variant angina: what to think in 2011?]

Spastic angina is considered rare but its prevalence is probably underestimated especially in case of atherosclerotic coronary lesions. Its diagnosis remains important due to its poor prognosis and therapeutic characteristics. We report three clinical cases illustrating two different clinical presentations and the problem of diagnosis of spastic angina. We performed a review of the literature essentially concerning commonly used diagnosis means and especially provocative testing for coronary spasm. This test needs to be adapted to the evolution of techniques and uses of coronary angiography in 2011, particularly the wide spread use of radial approach. Therefore new recommendations are needed, specifying the terms of provocative testing and establishing clear diagnosis criteria including clinical, electrocardiographic and angiographic data. Such guidelines would probably help to better diagnose and treat these patients in our practice.

Ischemia-modified albumin is a highly sensitive serum marker of transient myocardial ischemia induced by coronary vasospasm

BACKGROUND

Ischemia-modified albumin, a new marker of myocardial ischemia, is known to elevate during ischemia induced by percutaneous coronary intervention. It is, however, not known whether ischemia-modified albumin also elevates during transient coronary vasospasm.

METHODS

We evaluated ischemia-modified albumin in patients undergoing intracoronary ergonovine spasm provocation test (n=26). For additional comparison, ischemia-modified albumin was also evaluated in elective percutaneous coronary intervention patients (n=18) and in patients with normal coronary angiography (n=10). Blood samples were taken from the arterial sheath before the procedure, just after procedural completion, or balloon inflation.

RESULTS

Median ischemia-modified albumin level elevated significantly in patients with positive provocation test compared with baseline [n=16, 106.0 (interquartile range 96.5, 115.5) versus 128.5 (114.8, 171.8) U/ml, P<0.001], whereas it did not change in patients with negative provocation test [n=10, 109.5 (103.3, 115.0) versus 113.5 (104.0, 118.3) U/ml, P=0.108]. Ischemia-modified albumin was also higher after percutaneous coronary intervention [113.5 (101.0, 131.5) versus 151.0 (129.3, 231.0) U/ml, P<0.0001] and did not change in patients with normal coronary angiography [108.5 (99.3, 114.0) versus 110.0 (108.0, 114.0) U/ml, P=0.085]. Ischemia-modified albumin elevation higher than 9 U/ml after provocation test could detect the presence of coronary vasospasm, with an area under the receiver operating characteristic curve of 0.975 (95% confidence interval 0.921-1.000), with a sensitivity of 94% and a specificity of 99%. Serum albumin levels were within reference range for all patients and there was no significant relationship between albumin and baseline ischemia-modified albumin or postischemic ischemia-modified albumin.

CONCLUSION

Thus, ischemia-modified albumin may have a role as a biochemical marker for transient myocardial ischemia induced by coronary vasospasm.