The most impressive experimental drug Schering is developing is an anti-clot agent to prevent heart attacks.

FORBES: Magazine Article

They were also high in those taking aspirin which, counterintuitively, is often prescribed to reduce clot formation and thus prevent heart attacks.

ECONOMIST: Deep-vein thrombosis: Causing trouble | The

Premature deaths from heart disease - the single biggest killer - are down by a quarter since 1997, with a third more heart operations, twice as many patients receiving immediate access to clot-busting drugs and cholesterol lowering drugs now prescribed to 1.8 million people.

BBC: NEWS | UK | Politics | Full text: Blair on public services

The average clot size of those who smoked a cigarette in the six hours before their heart attack was 23 square millimetres.

BBC: Smoking

Researchers now believe that up to 85% of heart attacks occur when arterial plaques suddenly rupture, spilling toxic substances and triggering a massive clot.

FORBES: Anatomy Of A Heart Attack

For now, treatment of strokes is pretty much limited to Genentech's clot-busting drug, Activase, a tissue plasminogen activator, which is primarily used to treat heart attacks.

FORBES: Repairing The Brain