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

Incidence and Risk Factors Associated With Hospitalization for Variant Angina in Korea

This study aimed to determine the incidence and the risk factors of hospitalization for variant angina (VA) in Korean patients. Using the National Inpatient Sample (NIS) database, manufactured and released by the Health Insurance Review and Assessment Service (HIRA) in Korea, the incidence of hospitalization and rehospitalization for VA were calculated. The numbers of patients hospitalized for VA were estimated to be 14,362 in 2009, 17,492 in 2010, and 20,592 in 2011. The standardized incidence rates of hospitalization for VA were 31.4% in 2009, 36.5% in 2010, and 41.7% in 2011 (relative increase rate from 2009 to 2011, 33.0%, P for trend < 0.0001). VA patients predominantly belonged to the middle-age group between 40 and 69 years (75.5%), and there were 54.3% male. Based on the hospitalization episodes, the number of rehospitalization was calculated to be 879, 1141, and 1446 patients out of 1867, 2274, and 2677 patients from 2009, 2010, and 2011, respectively. The rates of rehospitalization for VA were 47.1% in 2009, 50.2% in 2010, and 54.0% in 2011 (P for trend < 0.0001). Age was an independent factor associated with rehospitalization for VA. Hospitalization for VA occurred most frequently in fall from 2009 to 2011. In conclusion, hospitalization rates for VA steadily increased from 2009 to 2011 in Korea, and about a half of VA patients was hospitalized more than once a year in 2009 to 2011. Proper health policy and patient education are warranted to control the high rate of hospitalization for VA.

Post-valvular surgery multi-vessel coronary artery spasm - A literature review

Coronary artery spasm (CAS) refers to the spontaneous or stimuli-induced transient, often localized and intense subtotal or total constriction/occlusion of the epicardial coronary artery, usually concomitant with angina pectoris with associated elevation of the ST segment on electrocardiogram (ECG). In this article, we present a literature review on post-valvular surgery CAS and report the clinical case of a 77 year-old man who experienced severe early post-aortic surgery chest pain and hemodynamic instability. Emergent coronary angiography revealed severe occlusion of multiple branches of both coronary arteries. The CAS was alleviated with intracoronary infusion of nitroglycerin.

Provocative testing for coronary reactivity and spasm

Coronary spasm is an important and often overlooked etiology of chest pain. Although coronary spasm, or Prinzmetal's angina, has been thought of as benign, contemporary studies have shown serious associated adverse outcomes, including acute coronary syndrome, arrhythmia, and death. Definitive diagnosis of coronary spasm can at times be difficult, given the transience of symptoms. Numerous agents have been historically described for provocative testing. We provide a review of published data for the role of provocation testing in the diagnosis of coronary spasm.

Myocardial ischaemia in patients with coronary endothelial dysfunction: insights from body surface ECG mapping and implications for invasive evaluation of chronic chest pain

AIMS

Coronary endothelial dysfunction (ED), by predisposing to abnormal vasomotion, may cause chest pain in individuals with non-obstructed coronary arteries. The aim of this study was to correlate the magnitude of coronary ED with the presence and extent of inducible myocardial ischaemia using body surface electrocardiogram (ECG) mapping in symptomatic patients.

METHODS AND RESULTS

In 30 patients with chest pain and angiographically normal coronary arteries or mild atherosclerosis, we studied endothelium-dependent responses with acetylcholine (ACH) and endothelium-independent function with nitroglycerin and adenosine in the left anterior descending artery. Eighty-lead body surface ECG maps were collected at baseline and after each dose of ACH. There was a significant correlation between the maximal change in epicardial diameter with ACH and the magnitude of ST-segment shift [r = -0.44 (95% CI: -0.097 to -0.69), P = 0.015]. Patients with ≥ 0.05 mV ST-segment shift/lead had greater epicardial vasoconstriction (31.6 vs. 15.6%, P = 0.019), and lower coronary flow reserve (2.9 vs. 3.6, P = 0.047) compared with those with ST-segment shift <0.05 mV. Four patients had inducible ischaemia with ACH in the absence of abnormal epicardial or global microvascular vasomotion (>20% decrease in diameter or <50% increase in blood flow).

CONCLUSIONS

This study demonstrates that abnormal vasomotion due to coronary ED is associated with myocardial ischaemia in patients with chest pain. The magnitude of ischaemia correlates with the extent of ED. A small subset of patients develop myocardial ischaemia during ACH infusion without significant abnormalities in epicardial or global microvascular endothelium-dependent blood flow responses.

Transient ST-segment elevation due to iatrogenic hyperthyroidism in a patient with normal coronary arteries

A 53-year-old man presented with angina pectoris and ST-segment elevation in V(1)-V(4) leads. Electrocardiogram changes and chest pain were completely resolved with nitroglycerine infusion. Coronary angiogram revealed normal epicardial vessels. These findings suggest that the acute myocardial ischemia was secondary to coronary vasospasm. From his medical history we learned that he was taking L-thyroxine and the dose had been increased two months previously. He was found to be in thyrotoxic state at admission. L-thyroxine treatment was withheld and diltiazem was given. He had no further symptoms. In conclusion we think that acute myocardial ischemia was likely secondary to L-thyroxine-induced coronary spasm.

Coronary abnormal response has increased in Japanese patients: analysis of 17 years' spasm provocation tests in 2093 cases

BACKGROUND

Abnormal coronary response on acetylcholine test is observed in patients with early coronary atherosclerosis.

OBJECTIVES

We analyzed retrospectively the abnormal response rate during 17 years of spasm provocation tests in 2093 consecutive patients.

METHODS

We performed 2093 spasm provocation tests, consisting of 1198 acetylcholine tests and 895 ergonovine tests, between January 1991 and December 2007. Spasm provocation test was mainly performed in patients with ischemic heart disease. Abnormal response was defined as transient >90% luminal narrowing during spasm provocation tests. We classified these 17 years into two periods: former period from January 1991 to December 2000, and the latter period from January 2001 to December 2007. In the former period, 1300 spasm provocation tests were performed and 793 spasm provocation tests were done in the latter period.

RESULTS

The incidences of hypertension, dyslipidemia, and diabetes mellitus were significantly increased in the latter period. The values of total cholesterol, triglycerides, and fasting blood sugar were also significantly increased in the latter period. The frequency of abnormal response in the latter period was significantly higher than that in the former period (46.0% vs. 33.2%, p<0.05). The frequency of abnormal coronary response to acetylcholine in the latter period was significantly higher than that in the former period (60.0% vs. 34.0%, p<0.01), whereas there was no difference concerning abnormal response of ergonovine between the two periods (31.9% vs. 30.7%, ns).

CONCLUSIONS

In Japanese patients, abnormal coronary response to acetylcholine has increased and coronary endothelial dysfunction is suggested to have progressed.

Recommendations for performing acetylcholine tests safely: STOP dangerous complications induced by acetylcholine tests (STOP DCIAT)

OBJECTIVES

We examined some recommendations for performing acetylcholine (ACh) tests safely.

METHODS AND RESULTS

We performed 1000 ACh tests from 1991 to December 2004. ACh was injected in incremental doses of 20/50/80 microg into the RCA and of 20/50/100 microg into the LCA. During these periods, we encountered various major/minor complications; 12 ventricular tachycardia (1.2%) necessary one dc, one ventricular fibrillation (0.1%) necessary dc, 3 shock like the left main stem spasm (0.3%), one cardiac tamponade necessary surgical drainage (0.1%), and 164 Paf (164/959:17.1%) necessary administration of antiarrhythmic agents to sinus rhythm in about one third patients (31.7%). We did not experience irreversible severe complications, such as acute myocardial infarction or death.

RECOMMENDATIONS

(1) Stand by direct current with pasting, (2) Thump version when ventricular tachycardia or fibrillation occurred, (3) Over infusion to avoid hypovolemia, (4) Perform angiography before complete spasm provocation if a severe spasm, (5) Drainage if cardiac tamponade occurred, (6) Cibenzoline or disopyramid administration when ACh induced paroxysmal atrial fibrillation, (7) Incremental ACh dose up should be performed, (8) Administer small amount of noradrenaline if shock observed and (9) Test shot should be performed before 1-min angiography.

CONCLUSIONS

We recommend STOP DCIAT for performing ACh tests safely.

ST-segment elevation in lead augmented vector right may also be caused by diffuse left main coronary artery vasospasm without fixed stenosis

ST-segment deviation in lead augmented vector right (aVR) is useful for evaluating patients with acute coronary syndrome (ACS). The ST-segment elevation in this aVR in the patient with clinically suspected acute coronary syndrome suggests a strong possibility of left main coronary artery (LMCA) obstruction due to fixed stenosis. In this article, we report the first case, to our knowledge, of ST-segment elevation in lead aVR due to diffuse LMCA spasm.

Generalized spasm of the right coronary artery after successful stent implantation provoked by intracoronary administration of ergonovine

Coronary spasm may be one of the reasons for the appearance of chest pain after successful percutaneous coronary interventions, and is potentially hazardous when myocardial ischemia occurs. Coronary spasm can be diagnosed by intracoronary administration of ergonovine as a selective spasm provocative test. We report here the case of a patient who had chest pain and ST segment elevation 10 days after successful right coronary artery stent implantation. Repeat angiography was performed, with results of no in-stent stenosis and no stenosis in other segments. Since coronary artery spasm was considered as a possible reason, a spasm provocative test was attempted. Following ergonovine administration (total dose, 50 mug) into the right coronary artery, severe spasm with 99% stenosis developed over the whole artery except the stented segment. Isosorbide dinitrate was injected immediately, and the provoked spasm was soon relieved. Intravascular ultrasound revealed no neointima at the stented segment and diffuse and mild low-echogenic concentric plaque at the distal as well as proximal segment of the stent. Most reports regarding coronary artery spasm provocative tests have focused on focal lesions before interventional therapy, or during interventional procedures. Although it is quite rare, potential coronary spasm should be considered when chest symptoms recur after percutaneous coronary interventions without angiographic representation.

The mystery of coronary artery spasm

Coronary artery spasm is an important cause of chest pain and myocardial ischaemia. It can be defined as an exaggerated contractile response of epicardial coronary artery smooth muscle to various stimuli but the underlying mechanism is not well understood. Recent studies have shown that the loss of endothelial vasodilatory function in conjunction with an increase in vascular smooth muscle constrictor sensitivity to calcium are the likely predisposing conditions for coronary spasm. This review highlights current understanding of the pathophysiology, predisposing factors, diagnostic and therapeutic approaches for coronary spasm.

Use of transoesophageal echocardiography during cardiac arrest in patients undergoing elective non-cardiac surgery

BACKGROUND

Sudden unexpected intraoperative cardiac arrests in patients undergoing elective non-cardiac operations are rare but catastrophic complications. The efficacy and utility of transoesophageal echocardiography (TOE) in the diagnosis and management of these events have not been reported earlier.

METHODS

Unexpected intraoperative cardiac arrests in patients undergoing elective non-cardiac operations were prospectively studied during a 6 yr period. In these patients, TOE was performed within 5 min after initiation of external chest compression to identify the causes of the cardiac arrests.

RESULTS

Among a total of 125 965 surgical operations, 10 patients who suffered intraoperative cardiac arrests were studied. The causes of the cardiac arrests including myocardial infarction in five, pulmonary embolism in two, and severe hypovolaemia and ventricular arrhythmia without specific pathology in the other two patients were correctly identified using TOE. Seven patients survived.

CONCLUSION

We conclude that TOE was useful in cardiac arrest during non-cardiac surgery for identifying or excluding pulmonary embolism and for directing investigations and treatment in those patients who had suffered myocardial infarction.