Does stopping alcohol actually reverse the cardiovascular damage?

Some of it, yes, some of it, possibly not. The reversible effects are well-documented: blood pressure falls meaningfully within weeks to months of alcohol cessation or significant reduction; AFib episode frequency decreases in men with alcohol-triggered AFib; sleep architecture improves; hs-CRP falls as hepatic inflammation and gut-permeability effects resolve; and the HRV improvements are measurable within 30 days of abstinence. These are real and clinically significant changes.

What is less clearly reversible is established atherosclerosis. If twenty years of hypertension partially driven by alcohol contributed to coronary artery calcium accumulation, that calcified plaque does not dissolve when you stop drinking. The CAC score does not improve with alcohol cessation. What does improve is the rate of future plaque progression, the stability of existing plaque (via lower hs-CRP), and the blood pressure load on arterial walls. Stopping drinking reduces the rate at which your Vascular Clock ticks forward. It does not turn back what has already accumulated. A CAC score after cessation tells you where you are starting from. (Roerecke & Rehm, BMC Medicine, 2014)

Cardiologist's calibrated position, Solid (1) for the reversible effects on blood pressure, sleep, and hs-CRP. Established atherosclerosis: not reversible through alcohol cessation.

What to do: Get a baseline CAC score if you have been a regular drinker for more than a decade and have never had one. What it shows will determine the urgency and nature of additional interventions beyond stopping drinking.

For the full picture, read The Bourbon Collector's Honest Reckoning.