Elevated Placental Growth Factor Levels Are Associated With Adverse Outcomes at Four-Year Follow-Up in Patients With Acute Coronary SyndromesTimo Lenderink; Christopher Heeschen; Stephan Fichtlscherer; Stefanie Dimmeler; Christian W. Hamm; Andreas M. Zeiher; Maarten L. Simoons; Eric Boersma · 2006