U.S. drugmaker Pfizer reported first-quarter profit above Wall Street estimates Tuesday, helped by cost cuts and better-than-expected sales of its heart disease drug, Vyndaqel.

On an adjusted basis, Pfizer earned 92 cents per share in the latest quarter, compared with analysts' expectations of 66 cents per share, according to LSEG data.

Investors are closely watching for any potential impact on Pfizer's vaccine business and any changes to recommendations for receiving flu, COVID and other shots under the new health secretary Robert F Kennedy Jr., a longtime vaccine skeptic.

Pfizer and other drugmakers are also at risk of proposed hefty duties on trade partners such as China, which is a key source of raw ingredients and supplies for the pharmaceutical and medical device industries.

Shares of the drugmaker, which have fallen 13.1% so far this year, rose 1% in premarket trading.

It reported total revenue of $13.70 billion for the first quarter, compared with analysts' expectations of $13.91 billion, according to LSEG data.