A number of comparative studies have been performed with metoprolol, a β 1-selective "second-generation" β blocker, and carvedilol, a nonselective and vasodilatative "third-generation" β blocker.

There is evidence to indicate that full adrenergic blockade by carvedilol improves survival and cardiovascular outcome in patients with heart failure compared with metoprolol treatment ...

Two protocols for switching between carvedilol, a third-generation nonselective agent with vasodilation through α 1 blockade, and a β 1-selective agent (e.g., metoprolol, atenolol) are described ...