The Wall Street Journal reports that CVS Health (NYSE: CVS) — the second largest pharmacy retailer and pharmacy benefit manager (PBM) — is offering more than $200 per share to acquire Aetna (NYSE: AET), a leading health insurer. The tie-up could help insulate CVS Health’s market share from competition from Amazon.com (NASDAQ: AMZN). Will this deal help CVS Health survive in an increasingly competitive market?