Optical coherence tomography and artificial intelligence for calcium quantification in coronary disease of diabetic patients

Background

Diabetes mellitus (DM) is associated with increased cardiovascular morbidity and mortality. Coronary artery disease in diabetic patients is characterized by a greater burden of lipidic plaques and calcifications. Little is known on the quantitative and qualitative characteristics of calcific plaques in diabetics vs non diabetics. The recent application of Artificial Intelligence (AI) to optical coherence tomography (OCT) enables unique evaluation of coronary calcification.

Purpose

To compare qualitative and quantitative characteristics of coronary calcified plaques in diabetic and non-diabetic patients using AI-OCT.

Methods and material

We recruited 78 patients admitted for chronic coronary syndrome (CCS) or acute coronary syndrome (ACS) undergone intracoronary imaging with OCT between January 2019 to October 2021. Differences in plaques characteristics assessed by Artificial Intelligence applied at OCT runs were compared in DM and non-DM population using generalized estimating equations. To estimate the burden of calcification we classified the calcific lesions according to the Fujino score, an OCT based calcium scoring system.

Results

A total of 78 patients were included (54 non-DM lesions, 29 DM lesions). The culprit lesion was examined by OCT in all patients without any peri- or postprocedural complications. The population was homogeneous for cardiovascular risk factors even if we observed a higher prevalence of peripheral arterial disease (PAD) in the DM cohort (22.2% vs 2% p value 0.003). There were no statistical differences in previous PCI or CABG but we observed more multivessel PCI in the history of DM patients if compared with non-diabetic ones (33.3% vs 11.8% p value 0.021). The clinical presentation in DM groups was more often unstable angina (22.2% vs 0% p value <0.001) while STEMI, NSTEMI or CCS had the same prevalence in the two cohorts. At baseline angiography, patients with diabetes had more often multivessel disease (29.6% vs 17.6% p=0.014) with all the vessels equally involved. There were no qualitative differences in plaque morphology but using the Fujino score to estimate the calcium burden in the two population we found hardest calcific plaques expressed by higher Fujino score more frequently in DM patients compared to non-DM ones (50% vs 26.9%, p=0.04 of Fujino score 4).

Conclusion

DM has an impact on atherosclerotic process and plaque remodeling. Applying AI methods at OCT plaque analysis, we can extract important and standardized information on calcium burden in diabetic. This might help the interventional cardiologist in image interpretation, therapeutic strategy decision, improving workflow and clinical outcomes.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): University of Florence

The role of calcification in cardiovascular outcome after left main bifurcation revascularization: a single centre experience

Introduction

Left main bifurcation (LMB) disease represents a high-risk subset of advanced coronary artery disease, often associated with severe calcification. Different stenting techniques have been evaluated to overcome challenges of the LMB anatomy, but the role of the calcific burden on cardiovascular (CV) outcome after LMB revascularization is unclear.

Purpose

We sought to evaluate the CV hospitalization predictors during follow-up of patients who underwent LMB revascularization (LMBR) in a high-volume center in Italy.

Methods

We performed a retrospective analysis of LMBR patients between 2018 and 2021. Patients were treated with different techniques in the acute or chronic settings and followed-up by telephone or outpatient visit. Coronary calcification (CC) was visually judged as absent, mild, moderate or severe. Predictors of CV hospitalizations were assessed.

Results

The median follow-up was 511 days. Among 129 patients who underwent LMBR during the study period, 32 (24.8%) were female, with a mean age of 72 (±10.6) years. 105 (81.4%) patients were hypertensive and 49 (38%) diabetics. The mean eGFR value was 66.3 (± 21.8) ml/min/m2. The majority of patients had three vessel disease (79, 61.3%), while only a small minority had one vessel disease (5, 3.9%). The mean SYNTAX score I was 27.1 (± 8.6), with most patients at intermediate risk (65, 50.4%) followed by patients at low (37, 28.7%) and high (27, 20.9%) risk. A provisional technique was used in most cases (79, 61.2%), followed by double-kissing crush (37, 28.7%) and T-stent/T-and-protrusion (13, 10.1%). Intravascular imaging was used in 84 (65.1%) cases. Most patients had no angiographic demonstration of CC (73, 57.9%), while when present, they were mild in 14 (11.1%), moderate in 29 (23%) and severe in 10 (7.9%) patients. Preparation of the CC was performed only with non-compliant (NC) balloons in mild CC (10, 71.4%) and with NC balloons (14, 48.3%) or intravascular lithotripsy (IVL) (13, 44.8%) in case of moderate CC. In the presence of severe CC, lesion preparation was carried out with IVL (4, 40%) or NC balloons (6, 60%). CC were associated with a more unfavorable outcome and, when present in a severe grade, resulted in a statistically significant risk of CV hospitalizations (HR 1.652; 95% CI 1.723–15.793; p=0.003) (Figure 1). After univariate and multivariate Cox regression analysis (Figure 2), only the presence of severe CC was associated with an increased risk of CV hospitalizations (HR 1.9; 95% CI 1.76–19.63; p=0.002), whereas aspirin therapy was a protective factor (HR −1.34; CI 0.07–0.86; p=0.02).

Conclusions

The presence of severe calcification is associated with a higher risk of CV hospitalizations, despite preparation of calcific lesions was always performed and intravascular imaging use was extensive. There were no differences in outcomes regardless to clinical presentation at admission, different stenting techniques and SYNTAX score I.

Funding Acknowledgement

Type of funding sources: None.