Background: Whereas the efficacy and safety of intravascular lithotripsy (IVL) have been confirmed in de novo calcified coronary lesions, little is known about its utility in treating stent underexpansion. This study aimed to investigate the impact of IVL in treating stent underexpansion. Methods and Results: Consecutive patients with stent underexpansion treated with IVL entered the multicenter IVL-Dragon Registry. The procedural success (primary efficacy endpoint) was defined as a relative stent expansion >80%. Thirty days device-oriented composite endpoint (DOCE) (defined as a composite of cardiac death, target lesion revascularization, or target vessel myocardial infarction) was the secondary endpoint. A total of 62 patients were enrolled. The primary efficacy endpoint was achieved in 72.6% of patients. Both stent underexpansion 58.5% (47.5–69.7) vs. 11.4% (5.8–20.7), p < 0.001, and the stenotic area 82.6% (72.4–90.8) vs. 21.5% (11.1–37.2), p < 0.001, measured by quantitative coronary angiography improved significantly after IVL. Intravascular imaging confirmed increased stent expansion following IVL from 37.5% (16.0–66.0) to 86.0% (69.2–90.7), p < 0.001, by optical coherence tomography and from 57.0% (31.5–77.2) to 89.0% (85.0–92.0), p = 0.002, by intravascular ultrasound. Secondary endpoint occurred in one (1.6%) patient caused by cardiac death. There was no target lesion revascularization or target vessel myocardial infarction during the 30-day follow-up. Conclusions: In this real-life, largest-to-date analysis of IVL use to manage underexpanded stent, IVL proved to be an effective and safe method for facilitating stent expansion and increasing luminal gain.

Rationale : New therapies for refractory angina are needed. Objective : Assessment of transendocardial delivery of bone marrow CD133 ⁺ cells in patients with refractory angina. Methods and Results : Randomized, double-blinded, placebo-controlled trial enrolled 31 patients with recurrent Canadian Cardiovascular Society II–IV angina, despite optimal medical therapy, ≥1 myocardial segment with inducible ischemia in Tc-99m SPECT who underwent bone marrow biopsy and were allocated to cells (n=16) or placebo (n=15). Primary end point was absolute change in myocardial ischemia by SPECT. Secondary end points were left ventricular function and volumes by magnetic resonance imaging and angina severity. After 4 months, there were no significant differences in extent of inducible ischemia between groups (summed difference score mean [±SD]: 2.60 [2.6] versus 3.63 [3.6], P =0.52; total perfusion deficit: 3.60 [3.6] versus 5.01 [4.3], P =0.32; absolute changes of summed difference score: −1.38 [5.2] versus −0.73 [1.9], P =0.65; and total perfusion deficit: −1.33 [3.3] versus −2.19 [6.6], P =0.65). There was a significant reduction of left ventricular volumes (end-systolic volume: −4.3 [11.3] versus 7.4 [11.8], P =0.02; end-diastolic volume: −9.1 [14.9] versus 7.4 [15.8], P =0.02) and no significant change of left ventricular ejection fraction in the cell group. There was no difference in number of patients showing improvement of ≥1 Canadian Cardiovascular Society class after 1 (41.7% versus 58.3%; P =0.68), 4 (50% versus 33.3%; P =0.63), 6 (70% versus 50.0%; P =0.42), and 12 months (55.6% versus 81.8%; P =0.33) and use of nitrates after 12 months. Conclusion : Transendocardial CD133 ⁺ cell therapy was safe. Study was underpowered to conclusively validate the efficacy, but it did not show a significant reduction of myocardial ischemia and angina versus placebo. Clinical Trial Registration : URL: http://www.clinicaltrials.gov . Unique identifier: NCT01660581.