Here's a ranking of popular diets by the AHA.
https://www.ahajournals.org/doi/full/10.1161/CIR.0000000000001146

Tier 1 in green scored the highest. Tier 4 in red scored the lowest.
100% - Dash diet/Nordic diet (Tier 1)
92% - Pescatarian diet (Tier 1)
89% - Mediterranean diet (Tier 1)
86% - Vegetarian diet (Lacto, ovo, ovo-lacto) (Tier 1)
78% - Vegan diet (Tier 2)
78% - Low-fat diet (TLC diet, Volumetrics) (Tier 2)
72% - Oil-free very low fat (Esselstyn, McDougall, Pritikin) (Tier 3)
64% - Low carb (South Beach, Zone diet) (Tier 3)
53% - Paleo (Tier 4)
31% - Keto (including Atkins) (Tier 4)