Revenues from our acute support line, which includes CentriMag and PediMag were $8.7 million compared with $4.4 million a year-ago, an increase of over 90%. We’re certainly pleased with the continued momentum in this product line, which include a growth in the core U.S. CentriMag business of 34% as well as approximately $2.7 million of incremental revenues recorded as a result of the Levitronix Medical transaction, over 90% of which were generate outside the U.S.
Lastly, revenues from the Thoratec product line, the PVAD and IVAD were 5.8 million versus 7.3 million a year ago, a decrease of 21%. We recorded strong year-over-year unit growth in the quarter selling 1,057 pumps, an increase of 23% versus 859 pumps in the first quarter a year ago. In the U.S. market, we shipped 838 pumps representing a 24% year-over-year increase, while internationally pump volume increased 20% in the first quarter of 2012 to 219 units. HeartMate unit volume expanded by 32% in both the U.S. and international markets, offsetting a significant decline in PVAD and IVAD units.
Internationally HeartMate II showed particular strength in both France and Germany, while in the U.S. we achieved strong growth in both the bridge-to-transplant and destination therapy indications. We have seen encouraging development of the referral process facilitated by our market development efforts in conjunction with the outreach efforts of many of our implanting centers, and we’re seeing clear evidence that our D.C. market development strategy is bearing fruit.
Going forward we will continue to focus our investment on this large and sustainable growth opportunity. An important growth driver during the quarter was the continued adoption of HeartMate II by our Group III implanting centers, which consists of smaller transplant and open heart centers. While we achieved HeartMate II unit growth in excess of 20% across each major group of centers. The most rapid growth continues to come from this third group, where volume roughly doubled year-over-year. This group now include 19 transplant centers and 48 open heart centers and during the first quarter contributed close to 20% of our U.S. HeartMate II unit sales.