Is pre-intervention intravascular ultrasound necessary in evaluating target lesion calcification in patients undergoing transcatheter therapy?

To identify a subset o patients with a high probability of extensive calcification for further intravascular ultrasound (IVUS) examination, the frequency and extent of target lesion calcification as assessed by IVUS and its correlations with age, gender and risk factors as well as the value of angiography in identifying ultrasound calcification were analyzed in 88 patients undergoing balloon angioplasty for significant coronary atherosclerotic stenosis. The extent of calcification was semi- quantitatively graded as 0: no calcification +: calcification arc <90°; ++: calcification arc from 90° to 180°; +++: calcification arc >180°. The distribution pattern of calcification was classified as superficial deep or mixed. The results indicate: (1) the frequency of target lesion calcification was 38.6%, of which 52.9% showed a superficial pattern and 56.0% had a calcification arc <90≡; and (2) only age was significantly associated with target lesion calcification in all of the patients. The frequency of calcification was remarkably higher in patients ≤ 60 years old than in patients ≤ 60 years old (61.9% vs 17.4%, p<0.001); (3) among patients less than 60 years old, those with calcification had a higher average number of risk factors than those without; and (4) the total sensitivity of angiography in identifying ultrasound calcification was 43.6%, with a significantly higher sensitivity for calcification arc > 180° and mixed pattern. In conclusion, pre-intervention IVUS may be necessary in patients ≤60 years old and in those <60 years old with more than two risk factors in selecting devices to optimize interventional strategies.