From what I know from as a general practitioner, NO and drugs that release NO do not prevent nor reverse coronary disease. Nitrates, so drugs that release NO, are commonly prescribed to treat coronary disease symptoms though. NO mainly dialates venes, not arteries, so the effect is due to less blood for the heart to pump, rather than more blood flowing through the coronary arteries.
I do not have any studies to cite here, but it is a well-established fact in the medical community, that nitrates only alleviate the symptoms of coronary disease, but do not decrease morbidity or overal survival.
I do not know about other cardiovascular diseases though. Coronary is what you deal with on a daily basis.