Prevalence and pattern of abnormal myocardial perfusion in patients with isolated coronary artery ectasia: study by 99mTc-sestamibi radionuclide scintigraphy

13N-Ammonia myocardial blood flow quantitation in patient with aneurismal coronary artery disease

Aneurysmal coronary artery disease includes coronary artery aneurysms and ectasia; this condition has been associated with poor long-term outcomes. Few studies have explored myocardial blood flow 13N-ammonia PET/CT MPI added value. We present a 45-year-old man who came to the emergency department with chest pain. After a physical examination and laboratory studies, he was diagnosed with very high-risk unstable angina and referred to the catheterization laboratory. Coronary angiography showed the culprit lesion in the LCx and was treated by angioplasty and stent. LAD was found with coronary artery ectasia (TIMI 2 flow grade) and the RCA with aneurysmal disease in the proximal and middle segments (TIMI 3 flow grade). Medical treatment was decided for these findings and the patient was discharged. Two weeks later, we performed a 13N-ammonia PET/CT MPI founding apical, inferior, and inferoseptal severe ischemia, and reduced hyperemic coronary blood flow and coronary flow reserve in the RCA territory. Flow was normal in the LAD territory. Although coronary angiography remains the gold standard for evaluating these coronary abnormalities, it does not show the physiological compromise. Therefore 13N-ammonia PET/CT MPI should be performed as a complementary noninvasive imaging approach.

Coronary artery ectasia: prevalence, angiographic characteristics and clinical outcome

Objective

Determine coronary artery ectasia (CAE) prevalence and clinical outcome in a large cohort of patients underwent coronary angiography.

Methods

In an 11-year period, between 2006 and 2017, 20 455 coronary angiography studies were performed at a large university centre. Patients diagnosed with CAE based on procedure report were included in the final analysis.

Results

CAE was diagnosed in 174 out of 20 455 studies (0.85% per total angiograms, 161 patients). Patients’ average age was 59.6±11.2 years old with male predominance (90.7%). Diffuse ectasia morphology was most common (78.9%), followed by fusiform (16.1%) and saccular (5%). Mixed CAE and atherosclerotic heart disease (ASHD) was present in 75.2% of the patients and isolated CAE in 24.8%. The most common coronary artery involved was the right coronary artery (RCA) (79%). Following index angiography, all the isolated CAE group was managed conservatively, while 67% of the mixed CAE-ASHD group underwent coronary intervention. In an average follow-up of 6±3.6 years, adverse clinical event (a composite endpoint of any death, cerebrovascular accident, myocardial infarction, thromboembolic event, bleeding and stent thrombosis) occurred in 48.8% of the mixed CAE-ASHD group compared with 25% in the isolated CAE group (p<0.05).

Conclusions

CAE is a rare phenomenon. The most common artery involved was the RCA, and the diffused type of CAE was the most frequent. Most patients with CAE have also concomitant ASHD, and those patients have higher mortality and complications rate, compared with isolated CAE disease.

SPECT/CT with 99mTc-sestamibi for the evaluation of skeletal muscle perfusion after electrical muscle stimulation in athletes

Objective

The purpose of this study was to evaluate the effects of electrical muscle stimulation (EMS) on muscles, using ^99mTc-sestamibi SPECT/CT.

Materials and Methods

We prospectively enrolled 20 consecutive male professional water polo players. The mean age was 25 years (range, 18-36 years). All athletes underwent ^99mTc-sestamibi SPECT/CT of the thigh (rectus femoris and vastus medialis muscle groups) before and after EMS. Images were quantified to identify increases in perfusion after EMS.

Results

Before EMS, there were no significant differences between the right and left thigh (rectus femoris and vastus medialis muscles) in terms of perfusion (p = 0.4). However, the comparison between the pre- and post-EMS analyses of the same muscle groups showed significant differences in radiotracer uptake (p < 0.001), with a mean increase in perfusion of 128% for the rectus femoris muscle group (95% CI: 0.86-1.61) and 118% for the vastus medialis muscle group (95% CI: 0.96-1.79).

Conclusion

^99mTc-sestamibi SPECT/CT is an objective means of evaluating blood flow in muscles submitted to EMS, which appears to promote significant increases in such blood flow.

The beneficial effects of renin-angiotensin system blockades on 2 year outcomes in coronary artery ectasia patients

OBJECTIVES

This study was designed to investigate the impact of renin-angiotensin system blockade (RASB) therapy with angiotensin-converting enzyme inhibitors or angiotensin-receptor blockers on the outcomes of coronary artery ectasia (CAE).

METHODS

The CAE patients identified by coronary angiography from our center were consecutively enrolled. We obtained the baseline discharge prescription of RASB from the medical records system and conducted follow-up through telephone interviews. Cox regression models, propensity score and subgroup analysis were used to assess the impact of RASB on all-cause mortality and non-fatal myocardial infarction. Both the unadjusted and adjusted Kaplan-Meier curves stratified by RASB therapy were plotted.

RESULTS

There were 595 patients with CAE in total and 333 (56.0%) were prescribed RASB therapy. Over a 2 year follow-up time, 16 all-cause deaths and 10 non-fatal myocardial infarctions were identified. Those patients treated with RASB had a significantly lower all-cause mortality and non-fatal myocardial infarction rate with an adjusted hazard ratio of 0.32 (95% confidence interval: 0.13 to 0.77, p = .011). The outcome benefits of RASB therapy were further confirmed in the propensity score analysis and subgroup analysis.

CONCLUSIONS

This observational study suggests that RASB therapy is associated with a lower risk of all-cause mortality and non-fatal myocardial infarction in patients with CAE.

Effect of Diltiazem on Coronary Artery Flow and Myocardial Perfusion in Patients With Isolated Coronary Artery Ectasia and Either Stable Angina Pectoris or Positive Myocardial Ischemic Stress Test

Isolated coronary artery ectasia (CAE) may be associated with stable or unstable coronary events despite the absence of epicardial coronary stenosis. Impaired coronary flow dynamics and myocardial perfusion have been demonstrated in stable patients with ectatic coronary arteries. We aimed to assess whether epicardial flow and tissue-level perfusion would be improved by diltiazem in myocardial regions subtended by the ectatic coronary arteries in patients with isolated CAE. A total of 60 patients with isolated CAE were identified of 9,780 patients who underwent elective coronary angiography. Patients were randomized to 5 mg of intracoronary diltiazem or saline. Coronary blood flow of the microvascular network was assessed using myocardial blush grade (MBG) technique. The thrombolysis in myocardial infarction (TIMI) flow grade and TIMI frame count (TFC) were used to assess epicardial coronary flow. MBG (from 2.4 to 2.6, p = 0.02), TIMI flow grades (from 2.4 to 2.8, p <0.001), and TFC (from 35 to 26, p <0.001) were significantly improved after diltiazem, whereas no significant change was noticed after saline (from 2.4 to 2.4, p = 0.86 for MBG; from 2.3 to 2.3, p = 0.71 for TIMI flow grade; and from 35 to 33, p = 0.43 for TFC). Diltiazem provided amelioration of the altered coronary flow dynamics, which was suggested as the pathophysiological influence of CAE. In conclusion, the favorable effects of the diltiazem on myocardial perfusion were observed at both epicardial and tissue levels.

Prognostic Value of Coronary Artery Stenoses, Markis Class, and Ectasia Ratio in Patients with Coronary Artery Ectasia

OBJECTIVES

To assess the prognostic value of coexisting coronary artery disease (CAD), Markis class, and ectasia ratio for major adverse cardiovascular events in patients with coronary artery ectasia (CAE).

METHODS

A total of 512 consecutive patients with angiographically proven CAE were enrolled. Coronary ectasia extent was graded using the Markis class, and ectasia severity was assessed based on the ectasia ratio. Patients were followed up for a median of 34.6 months.

RESULTS

In the current study, 76 cases had isolated CAE, while the remaining 436 cases had coexisting CAD (mixture CAE). Males (84.4%) were predominantly affected, and the right coronary artery (55.1%) was most commonly involved. During follow-up, 86 overall major adverse cardiovascular events were diagnosed. Kaplan-Meier analysis failed to reveal any differences between isolated and mixture CAE in both cumulative and event-free survival analyses (p=0.429 and p=0.277, respectively). Moreover, when patients were divided into 4 groups according to Markis class (type I-IV) or 2 groups based on the ectasia ratio (1.5-2.0 and >2.0), there was no significant difference in survival outcomes among the groups (p>0.05).

CONCLUSIONS

In this follow-up study with a relatively large sample, the survival rate of patients with CAE appeared to be independent of coexisting CAD and ectasia extent and severity.