Case presentation

A 58-year-old man, with a history of documented coronary artery disease found by catheterization 4 years earlier, remained asymptomatic on medical therapy until he presented to his cardiologist with a 6-week history of dyspnea and chest tightness occurring with minimal exertion. Medical therapy consisted of simvastatin, niacin, aspirin, metoprolol, and long-acting nitrates. His past history is also remarkable for diet-controlled diabetes mellitus, hypertension, dyslipidemia, and hypothyroidism. He actively smokes tobacco. The physical exam, electrocardiogram, and routine laboratory evaluations were all normal. Diagnosed with crescendo angina pectoris, he was referred for cardiac catheterization.

Cardiac catheterization

Ventriculography revealed normal left ventricular function. Coronary angiographic findings included a codominant circulation, with a diffusely diseased but small right coronary artery (Figure 5-1) and moderate distal disease in the left circumflex and obtuse marginal branches (Figures 5-2, 5-3). The proximal segment of the left anterior descending artery contained moderate disease (Figure 5-2 and Video 5-1) that in some views appeared nonobstructive (Figures 5-2, 5-3) but in other views appeared more concerning (Figure 5-4 and Video 5-2). Much of the disease present on this study appeared similar to the appearance on angiography 4 years earlier, leaving the operator at a loss for the dramatic change in symptoms.

FIGURE 5-1 A small, diffusely-diseased right coronary artery is present but is unchanged from a prior angiogram.

FIGURE 5-2 This view shows the moderate distal disease in the left circumflex and obtuse marginal artery (arrows); there is also moderate disease in the left anterior descending artery (double arrow).

FIGURE 5-3 In this left anterior oblique view of the left coronary artery with cranial angulation, the disease in the left anterior descending artery does not appear significant.

FIGURE 5-4 This left anterior oblique view with caudal angulation suggests a significant lesion in the left anterior descending artery (arrow).

The concerning symptoms, along with an ambiguous lesion in the proximal left anterior descending artery, prompted the operator to measure fractional flow reserve of this vessel (Figure 5-5). After a 6 French guide catheter was inserted, a pressure wire was advanced past the lesion and hyperemia induced with 100 μg of intracoronary adenosine; fractional flow reserve measured 0.69. Thus, the angiographically-moderate disease represented a flow-limiting lesion, and the operator decided to treat the lesion percutaneously. Following the administration of intravenous heparin and eptifibatide, the procedure began with balloon predilatation, using a 2.5 mm by 20 mm long compliant balloon. At nominal inflation pressure, a significant waist remained in the compliant balloon (Figure 5-6