Table 1. The characteristics and summary of findings of articles included in this review.

CAD; coronary artery disease; AHA: American Heart Association; hs-CRP: highly-sensitive C-reactive protein; PCI; percutaneous coronary intervention; LDL-C: low-density lipoprotein cholesterol; CARDIA: Coronary Artery Risk Development in Young Adults; MPO: myeloperoxidase; MMP: metalloproteinase

Author/Year/Title	Study Design	Study Population /Sample Size	Diet and targeted outcome	Summary	Limitation of study
1. Shah et al, 2018 [1].	A randomized, open-label, blinded end point study design.	100 participants from New York University Langone Medical Center with a history of angiographically defined CAD underwent 1:1 randomization to either a vegan diet or the AHA-recommended diet.	Vegan diet versus the AHA-recommended diet. Outcome: hs-CRP concentration, inflammatory markers, white blood cell cellular adhesion molecules, anthropometric data, glycemic markers, lipid profiles, and quality of life as measured by the EuroQol 5 dimensions questionnaire	It showed a considerably higher decrease in hsCRP with a vegan diet compared to the AHA's diet recommendation. However, there was no significant difference in the degree of weight loss and waist circumference	The study was not powered to assess for differences in major adverse cardiovascular and cerebrovascular events, also participants may have underreported their intake on the food records.
2. Djekic D et al, 2020 [9].	A randomized, open-label, cross-over study	Participants with CAD treated with PCI and on optimal medical therapy/ 27 participants	A lacto-ovo-vegetarian diet allowing the intake of eggs and dairy products. Outcome: oxidized LDL-C selected cardiometabolic risk factors, gut microbiota, and plasma metabolome.	This study revealed that a vegetarian diet compared with a diet including daily meat consumption improved plasma lipid profile, particularly triacylglycerol, phosphatidylcholine, alkylphosphatidylcholine, and sphingomyelin in coronary artery disease. Results of this study support that a vegetarian diet may be beneficial for secondary prevention of CAD via modulation of lipid profile.	Small study size and the few women subjects in the study which may decrease generalizability.
3. Wright N et al, 2017 [10].	A prospective, two-arm, parallel, superiority study	Ages 35–70, from a general practice in Gisborne, New Zealand,  diagnosed with obesity or overweight and at least one of type 2 diabetes, ischaemic heart disease, hypertension, or hypercholesterolemia/ 65 participants	Low-fat plant-based diet. Outcome: BMI and dyslipidemia	The programme led to significant improvements in BMI, cholesterol, and other risk factors. It also achieved greater weight loss at 6 and 12 months than any other trial that does not limit energy intake or mandate regular exercise.	The study population had a higher number of females and a higher mean age.
4. Choi Y et al, 2021 [11].	Prospective study	Participants were 4946 adults in the CARDIA prospective study.	Plant-centered diet. Outcome: incident Cerebrovascular disease	Consumption of a Plant-centered diet, starting in young adulthood is associated with a lower risk of CVD by middle age.	The nature of the observational study design, unmeasured or residual confounding could not be ruled out.
5. Navarro et al, 2016 [12].	Observational cross-sectional study	329  Male volunteer	Vegetarian diet (lacto-ovo-vegetarian, lacto-vegetarian or vegan) versus Omnivores/ matrix metalloproteinases-2 and 9	The study found significantly lower concentrations of MPO, MMP-9, MMP-2, and MMP-9/TIMP-1 ratio in VD compared to omnivores (all P-value < 0.05).	Causal inference may be limited due to its cross-sectional study design.
6. Lara KM et al, 2019 [13].	Prospective cohort study	16,068 participants (mean age 64.0 + 9.1 years)	1. Convenience dietary pattern (more on meat dishes, pasta, Mexican dishes, pizza, fried potatoes, Chinese dishes, and fast food). 2. Plant-based pattern (more on cruciferous vegeta- bles and other vegetables, fruit, beans, and fish). 3. Sweets/fats pattern (more on desserts, bread, sweet breakfast foods, chocolate, candy, solid fats and oils, and miscella- neous sugar). 4. Southern pattern, (more on fried food, organ meats, processed meats, eggs, added fats, and sugar’sweetened beverages). 5. Alcohol/salads (more on wine, liquor, beer, leafy greens and salad dressing). Outcome: Incident heart failure	Adherence to a plant-based dietary pattern was inversely associated with incident HF risk, whereas the Southern dietary pattern was positively associated with incident HF risk.	Misclassification from inaccuracies of reporting dietary intake in the food frequency questionnaire (FFQ) likely occurred. The potential for residual confounding and a study population that did not include individuals with race/ethnicity other than non-Hispanic black or white may have altered and/or limited the generalizability of the results.