Ann Thorac Surg 2008;86:994-995. doi:10.1016/j.athoracsur.2008.02.094
© 2008 The Society of Thoracic Surgeons
Case Reports
Coronary Artery Spasm: A Rare But Important Cause of Postoperative Myocardial Infarction
Linrui Ray Guo, MDa,*,
Mary Lee Myers, FRCSCa,
Eva L. Kuntzb
a Division of Cardiac Surgery, London Health Science Centre, London, Ontario, Canada
b University of Heidelberg, Heidelberg, Germany
Accepted for publication February 29, 2008.
* Address correspondence to Dr Guo, Division of Cardiac Surgery, London Health Sciences Centre, 339 Windermere Rd, Suite B6 112, London, Ontario, N6A 5A5, Canada (Email: linrui.guo{at}lhsc.on.ca).
 |
Abstract
|
|---|
Myocardial infarction that is attributed to native coronary artery spasm in the early postoperative phase has rarely been documented. We report three cases of postoperative myocardial infarction secondary to angiographically demonstrated coronary spasm. Native coronary artery spasm is a rare, but important cause of postoperative ischemia and infarction. Suspicious electrocardiographic changes warrant consideration of transesophageal echocardiography to detect unexpected wall motion abnormalities. Established treatments include intravenous or intracoronary infusion of nitroglycerin and calcium channel antagonists, although several new therapeutic agents may also be beneficial. Prompt coronary angiography is the only definitive modality for early diagnosis and targeted treatment.
|
Introduction
|
|---|
There are a number of potential causes for postoperative myocardial ischemia and infarction. Vasospasm involving a native coronary artery or bypass conduit has been the subject of several case reports [1–6]. Establishing a diagnosis of coronary artery or graft spasm is not an easy task, as it involves bringing an intubated unstable patient to a catheterization laboratory for emergency angiography. We recently encountered 3 patients with postoperative myocardial ischemia and infarction secondary to angiographically documented native coronary artery vasospasm.
|
Case Reports
|
|---|
Patient 1
A 63-year-old woman underwent uneventful off-pump left internal thoracic artery to left anterior descending artery (LAD) grafting for persistent angina despite previous LAD stenting. Preoperative angiography demonstrated a 90% stenosis proximal to the stent and a 60% in-stent stenosis. The right coronary artery and circumflex artery were normal, as was the left ventricular function. She started to complaint of chest pain shortly after extubation 4 hours postoperatively. The electrocardiogram showed significant inferior lead ST-segment elevation. She was treated with intravenous nitroglycerin with some improvement, but showed a decreasing cardiac index and developed recurrent anginal pain. Coronary angiography demonstrated a patent left internal thoracic artery to the LAD graft, but diffuse thread-like narrowing in the distal LAD, and the posterior descending and posterolateral branches of the right coronary artery. Intracoronary administration of nitroglycerin and verapamil resulted in a slight improvement in the posterior descending caliber. There was akinesis of the left ventricular anteroapical and inferior segments, and a subsequent transthoracic echocardiogram showed an apical thrombus. Her troponin I and creatine kinase levels peaked at 53 ng/mL and 1,908 international units per liter, despite treatment with intravenous nitroglycerin. She was discharged home 2 weeks postoperatively, and subsequently she did well.
Patient 2
A 51-year-old man (who is a truck driver) was admitted with an acute coronary syndrome and a history of multiple episodes of amaurosis fugax. Angiography demonstrated a 75% proximal LAD stenosis, occluded circumflex artery, normal right coronary artery, and normal left ventricular function. He was also found to have bilateral subclavian stenoses, a severe left internal carotid artery stenosis and right internal carotid artery occlusion. He underwent uneventful combined left carotid endarterectomy and on-pump coronary bypass grafting with bilateral free internal thoracic artery grafts. An electrocardiogram 2 hours postoperatively showed significant ST-segment depression in leads I and V2–V6 and a transesophageal echocardiogram demonstrated inferoposterior akinesis. A coronary angiogram demonstrated patent grafts, but diffuse right coronary artery vasospasm starting from the mid vessel and extended into the distal branches (Fig 1A). Intracoronary verapamil and nitroglycerin resulted in rapid resolution of the electrocardiographic changes, but a 50% narrowing remained distally (Fig 1B). An intra-aortic balloon pump and intravenous nitroglycerin and diltiazem were started. Troponin I and creatine kinase peaked at 49 ng/mL and 654 international units per liter, respectively. He had a similar episode when switched from intravenous to oral diltiazem on postoperative day 1, which quickly resolved after reinstituting intravenous diltiazem. He was eventually switched to the oral form on postoperative day 5 and was discharged home on postoperative day 10.
View larger version (90K):
[in this window]
[in a new window]
|
Fig 1. (A) Pre-intracoronary and (B) post-intracoronary infusions of nitroglycerin and verapamil in patient 2.
|
|
Patient 3
A 39-year-old man underwent an elective Bentall procedure for severe aortic insufficiency and an ascending aortic aneurysm. A preoperative angiogram by magnetic resonance image angiographic scan demonstrated normal coronary arteries. ST-segment elevation on anteroseptal leads occurred in 3 hours postoperatively. A transesophageal echocardiography demonstrated anteroapical akinesis and inferior hypokinesis. An emergency angiography demonstrated widely patent re-implanted left and right coronary arteries, but diffuse narrowing in the middle and distal LAD. He was treated with intravenous nitroglycerin and diltiazem with minimal angiographic improvement. Troponin I rose to > 100 ng/mL and creatine kinase rose to 2,246 international units per liter. He was clinically well at the 3-month follow-up, but an echocardiogram showed a persistently depressed left ventricular ejection fraction of 35%.
|
Comment
|
|---|
The generally reported incidence of postoperative myocardial infarction is 3% to 5%, although this varies significantly with the diagnostic criteria used [7]. Potential causes include suboptimal myocardial preservation and acute graft or native coronary occlusion. Vasospasm involving either a graft or coronary artery has also been sporadically reported as a cause of postoperative myocardial ischemia and infarction [1–6]. The limited reports in this regard may reflect the diagnostic challenge involved as coronary angiography is required for accurate diagnosis. However, it is important to differentiate vasospasm from graft or coronary occlusion as the therapeutic responses to each scenario differ greatly. Patients with an acutely occluded graft or coronary artery may require emergency surgical or percutaneous intervention, whereas vasospasm generally requires aggressive pharmacologic management. We believe that the key to a timely diagnosis is a prompt transesophageal echocardiogram or a transthoracic echocardiogram to screen for any unexpected wall motion abnormality, and an angiogram to confirm the vasospasm. The value of cardiac markers is limited in this setting as time delay is needed to detect a meaningful rise.
Coronary artery spasm has long been recognized as a cause of myocardial ischemia. The biochemical basis of vascular reactivity is complex and depends on a balanced interplay between vascular smooth muscle and a large number of interacting substances that affect endothelial function. A deficiency of endothelial-derived nitric oxide seems to be of particular importance [8].
The mainstays of treatment of perioperative vasospasm are intravenous or intracoronary nitroglycerin and calcium channel antagonists, whereas milrinone and intra-aortic balloon pump insertion may be required in hemodynamically unstable patients. Early correction of hypomagnesemia with magnesium sulphate may be of benefit in prevention [6]. Responses to treatment can be variable as reflected in the current report. In cases of persistent or severe spasm, clinical success has been reported with new therapeutic agents such as the Rho-kinase inhibitor fasudil [1], calcium sensitizers such as levosimendan [2], nicorandil, [3] and phosphodiesterase inhibitors such as sildenafil [4]. Multiple stent placements for a vasospastic right coronary artery after coronary artery bypass grafting has also been described [5].
Although postoperative coronary artery and graft vasospasm is not commonly encountered clinically, it can result in significant myocardial infarction and patient morbidity. Any suspicious postoperative electrocardiographic changes should be investigated with a transesophageal echocardiography. New-onset wall motion abnormalities in segments perfused by normal coronary arteries suggest the possibility of coronary vasospasm, and emergency angiography should be considered.
|
References
|
|---|
- Inokuchi K, Ito A, Fukumoto Y, Matoba T, Shimokawa H. Usefulness of fasudil, a Rho-kinase inhibitor, to treat intractable severe coronary spasm after coronary artery bypass surgery J Cardiovasc Pharmacol 2004;44:275-277.[Medline]
- Döpfmer UR, Braun JP, Grosse J, Konertz W. Temporary left ventricular assist and levosimendan for coronary artery spasm Interact Cardiovasc Thorac Surg 2005;4:316-318.[Abstract/Free Full Text]
- Kimura N, Kawahito K, Adachi K, et al. Effects of intra-coronary and intra-graft administration of nicorandil for coronary spasm after coronary artery bypass grafting Kyobu Geka 2006;59:71-77.
- Fung E, Fiscus RR, Yim AP, Angelini GD, Arifi AA. The potential use of type-5 phosphodiesterase inhibitors in coronary artery bypass graft surgery Chest 2005;128:3065-3073.[Medline]
- Kaku B, Ikeda M, Kato H, Takabatake S, Hayashi T, Aoki S. Coronary artery multistenting in the treatment of life-threatening refractory coronary spasm after coronary artery bypass grafting Int Heart J 2007;48:379-385.[Medline]
- Minato N, Katayama Y, Sakaguchi M, Itoh M. Perioperative coronary artery spasm in off-pump coronary artery bypass grafting and its possible relation with perioperative hypomagnesemia Ann Thorac Cardiovasc Surg 2006;12:32-36.[Medline]
- Benoit M, Paris M, Sileran J, Fiemeyer A, Moatti N. Cardiac troponin I: Its contribution to the diagnosis of perioperative myocardial infarction and various complications of cardiac surgery Crit Care Med 2001;29:1880-1886.[Medline]
- Yasue H, Kugiyama K. Coronary spasm: clinical features and pathogenesis Intern Med 1997;36:760-765.[Medline]
Top
Abstract
Introduction
