Introduction The Quartet™ 1458Q left ventricular (LV) lead with a quadripolar CRT-D provides vector selection from four pacing electrodes resulting in 10 LV lead pacing configurations. Purpose: The Quadripolar Post-Approval Study is a prospective, multi-center study to assess acute and chronic performance of the Quartet 1458Q LV lead in patients indicated for cardiac resynchronization therapy (CRT). Methods Implanted subjects are followed for 60 months post implant. LV pacing capture threshold (PCT) and impedance values of final programed vectors are measured at each visit. Results Of 1,970 subjects enrolled (mean age 69 ± 11 years; 74 % men), 1,915 (97.2%) were successfully implanted. Mean follow-up time for all implanted subjects is 3.2 + 1.7 years. The LV lead was implanted in a lateral location in 47.6% (923/1970) of subjects. Mean PCT of the programmed vectors is 1.33 ± 0.93 V while mean impedance is 743.4 ± 282.8 Ω. Mean PCT and impedance measurements of the final programmed vectors at each follow-up visit are shown below. All 10 vectors have been used in at least one subject. Subjects with a vector change between baseline and 12 months (46%) account for 79.9% of all vector changes. A majority of changes (14.1%) have occurred from Vector 1 (bipolar configuration) to Vectors 3 and 5 (unipolar configurations). Reasons for vector programming are optimal capture threshold (79.7%), site of latest activation from CRT toolkit (5.3%) and no phrenic nerve stimulation (PNS) (4.3%). Estimated survival probability for LV lead-related complications at 60 months is 95.15% with 95% CI (93.87%, 96.17%). A total of 89 PNS adverse events have been reported in 71 subjects (3.7%), with 79.8% (71/89) resolved by device re-programing. There are 57 LV lead dislodgements in 54 subjects (2.8%). Conclusion The Quartet™ 1458Q LV lead has a high implant success rate, stable PCT and impedance across vectors over time with a low incidence of PNS. These results demonstrate the Quartet LV lead is reliable in delivering CRT using multiple pacing vectors providing physicians with a non-invasive option to meet the changing lead/patient interface without compromising electrical performance.