Cocarboxylase, also known as thiamine pyrophosphate (TPP), is the active coenzyme form of vitamin B1 (thiamine). Its role in cardiovascular health is primarily rooted in its essential function in carbohydrate metabolism and energy production, including in the myocardium (heart muscle). Thiamine deficiency can result in beriberi, a condition characterized by peripheral neuropathy, heart failure, and, in severe cases, cardiac weakness (so-called "wet beriberi"). In clinical practice, thiamine supplementation (sometimes as cocarboxylase) is indicated to treat or prevent deficiency, particularly in patients with heart failure who are at risk due to diuretic therapy or malnutrition.

There is some scientific evidence supporting the use of thiamine or cocarboxylase in the context of heart failure secondary to deficiency. Several small clinical studies and case reports have shown symptomatic improvement in cardiac function after thiamine supplementation in heart failure patients with low thiamine levels. However, robust clinical trials are limited, and the benefit appears to be most clear in deficiency states rather than as a general treatment for all causes of "heart weakness." Therefore, the evidence supports its use in specific clinical scenarios but not as a universal treatment for cardiac weakness.

In summary, cocarboxylase is scientifically justified in treating heart conditions linked to thiamine deficiency, but broader claims for its use in heart weakness lack strong evidence.