Aetna’s first-quarter net income soared 36 percent, fueled by gains from a multi-billion-dollar acquisition, and the health insurer hiked its 2014 earnings forecast above Wall Street expectations.

Its results breezed past analysts’ expectations, and Aetna shares jumped more than 4 percent in premarket trading.

The Hartford, Conn., insurer closed a $6.9 billion acquisition of fellow insurer Coventry Health Care last May, and it said today that deal was the main factor behind its growth in this year’s first quarter.

Aetna is the nation’s third-largest health insurer, and its medical enrollment swelled 24 percent in the quarter to 22.7 million people, compared to 2013.

Aetna shares climbed $3.09, or 4.5 percent, to $72 in premarket trading about two hours ahead of the market open.