Optical Coherence Tomography Guidance In The Management Of Acute Coronary Syndrome Based On Plaque Morphology

BACKGROUND

Acute coronary syndrome (ACS) is one of the leading causes of death worldwide. It is characterized by the formation of coronary artery thrombus which can be either due to plaque rupture, plaque erosion or rupture of a calcific nodule. The aim of study was to assess the plaque morphology leading acute coronary syndrome using OCT and to guide management based on its findings. It was an observational study, conducted at Rawalpindi Institute of Cardiology from Jan to Dec 2019.

METHODS

Fifty patients meeting the inclusion criteria were included in the study. OCT procedure was performed following intracoronary injection of 100-150 ug of nitroglycerine. The imaging catheter (OFDI dragon view) of the OCT device (Terumo Luna wave OFDI, Tokyo, Japan) was inserted into the culprit artery. Blood clearance was achieved by injecting diluted iodinated contrast at the rate of 5 ml/sec. Imaging acquisition was obtained following automated pullback at the rate of 25 mm/sec. Pathologies like stent under deployment, mal-apposition, strut fracture, plaque erosion, plaque rupture were assessed by the operating interventionist well versed with the OCT technology and lesion assessment. Data analysis was done using the SPSS version 26. Categorical variables were presented as counts and percentages while continuous variables as mean±SD.

RESULTS

A total of 50 patients were included in the study. The mean age was 49.24±11.92. Majority of the patients were male comprising 78.0% of the cases. Plaque rupture was the most common underlying pathology seen in 32.5% of the patients and exclusively in STEMI patients which required stent deployment. Thin cap fibroatheroma was seen in 27.9% of the cases while lipid rich plaque in 23.2% of the cases; again, requiring stent deployment. 9.3% of the cases had plaque erosion while 4.6% had calcific nodule and only 2.3% had intramural hematoma which were treated conservatively. 42.8% of the stent thrombosis patients had under-deployed stents requiring balloon dilatation while 14.2% had mal-apposed stent again requiring balloon dilatation. In contrast 14.2% each had neo-atherosclerosis, stent strut fracture and uncovered stent struts as the underlying pathology for stent thrombosis each requiring stent deployment.

CONCLUSIONS

OCT guided PCI in cases of acute coronary syndrome is a valuable modality that gives insight into the underlying pathology of the disease process and also guides in proper management.

Subclinical Left Ventricular Dysfunction In Patients With Isolated Severe Rheumatic Mitral Stenosis Having Normal Left Ventricular Ejection Fraction

BACKGROUND

Mitral stenosis (MS) is a prevalent disease in the developing world. It is a preventable disease associated with considerably high morbidity and mortality rates. Myocarditis secondary to rheumatic MS can cause left ventricular (LV) dysfunction. In majority of the case this LV dysfunction is subclinical. Recent development in imaging techniques like tissue Doppler imaging (TDI) and strain imaging enabled us to detect subclinical LV dysfunction. One such example is Global Longitudinal Strain (GLS), which is a reliable mean of assessing LV dysfunction in patients diagnosed with mitral stenosis. This study is design to determine the frequency of subclinical LV dysfunction in patients presenting with severe MS of rheumatic etiology in our institute. Objective of the study was to determine frequency of subclinical LV dysfunction by mean GLS in patients with isolated severe Rheumatic MS having normal LV Ejection fraction measured by 2D/M-mode echocardiography. It was an observational crosssectional study, conducted at Department of Cardiology, Rawalpindi Institute of Cardiology, Rawalpindi, during the period of six months from 1st January to 30th June 2016.

METHODS

Fiftyfive patients with isolated severe mitral stenosis of underlying rheumatic aetiology with preserve LV function (EF>50%) were selected as per other inclusion and exclusion criteria. All patients were evaluated with detailed history, physical examination and echocardiographic examination. GLS was also noted and all other information was recorded on data collection form.

RESULTS

The average age and mean GLS was 48.20±11.62 years and -19.24±1.15% respectively. Left ventricular systolic impairment in patients under study using the Global Longitudinal Strain was seen in 16.36% (9/55) cases.

CONCLUSIONS

Our results suggest that GLS helps in detecting impairment of LV systolic function at an early stage in patients with mitral stenosis which helps in their risk stratification thus warranting their early management.