Coronary restenosis of in-stent protruding bump with rapid progression: Optical frequency domain imaging and

Kenji Kawai1, Hirokuni Akahori1, Takahiro Imanaka1

  • 1Division of Cardiovascular Medicine and Coronary Heart Disease, Hyogo College of Medicine, 1-1 Mukogawa-cho, Nishinomiya, Hyogo 663-8501, Japan.

Insights

Recurrent in-stent restenosis (ISR) after drug-eluting stent (DES) implantation is rare but possible. Multimodality imaging aids in diagnosing complex ISR morphologies, guiding treatment for challenging coronary artery disease cases.

Area of Science:

  • Cardiovascular Medicine
  • Interventional Cardiology
  • Medical Imaging

Background:

  • In-stent restenosis (ISR) remains a significant challenge following percutaneous coronary intervention (PCI), even with advanced drug-eluting stent (DES) technology.
  • This case highlights a rare instance of recurrent ISR in a patient with non-ST elevation acute coronary syndrome (NSTE-ACS) undergoing hemodialysis.

Observation:

  • The patient presented with recurrent NSTE-ACS, and coronary angiography revealed ISR in the left circumflex artery (LCx) previously treated with DES.
  • Intravascular imaging, including optical frequency domain imaging and angioscopy, identified an eccentric protruding mass with an irregular, high-backscatter surface, described as an in-stent bump.

Findings:

  • Despite successful treatment of the ISR lesion with a drug-coated balloon, the patient experienced further NSTE-ACS due to new de novo lesions and re-restenosis.
  • Multimodality assessment proved crucial in diagnosing the complex morphology of the recurrent restenosis, including a calcified nodule.

Implications:

  • The presence of an in-stent protruding bump on intravascular imaging may indicate a higher risk of recurrent ISR.
  • Multimodality imaging assessment is valuable for differentiating ISR tissue and guiding management strategies in complex coronary artery disease.
  • This case underscores the importance of comprehensive assessment and tailored treatment approaches for patients experiencing ISR after DES implantation.

Related Concept Videos

Linear Approximation in Frequency Domain01:26

Linear Approximation in Frequency Domain

Linear systems are characterized by two main properties: superposition and homogeneity. Superposition allows the response to multiple inputs to be the sum of the responses to each individual input. Homogeneity ensures that scaling an input by a scalar results in the response being scaled by the same scalar.
In contrast, nonlinear systems do not inherently possess these properties. However, for small deviations around an operating point, a nonlinear system can often be approximated as linear....
375
Frequency-Domain Interpretation of PD Control01:24

Frequency-Domain Interpretation of PD Control

Proportional-Derivative (PD) controllers are widely used in fan control systems to improve stability and performance. A fan control system can be effectively represented using a Bode plot to illustrate the impact of a PD controller through its transfer function. The Bode plot visually conveys how PD control modifies the fan's response across various frequencies, providing a frequency domain interpretation of the controller's behavior.
The proportional control gain, combined with the...
367
Time and frequency -Domain Interpretation of PI Control01:27

Time and frequency -Domain Interpretation of PI Control

Proportional-Integral (PI) controllers are essential in many control systems to improve stability and performance. They are commonly used in everyday devices like thermostats to enhance system damping and reduce steady-state error. When the zero in the controller's transfer function is optimally placed, the system benefits significantly in terms of stability and accuracy.
Acting as a low-pass filter, the PI controller slows the system's response and extends settling times. This requires...
411
Time and frequency -Domain Interpretation of Phase-lead Control01:24

Time and frequency -Domain Interpretation of Phase-lead Control

Phase-lead controllers are commonly used in various control systems to enhance response speed and stability. Adjusting the brightness on a television screen offers a practical example of phase-lead control. When contrast is enhanced, a phase-lead controller is employed. Mathematically, phase-lead control is identified when the first parameter is smaller than the second.
The design of phase-lead control involves the strategic placement of poles and zeros to balance steady-state error and system...
451
Time and frequency -Domain Interpretation of Phase-lag Control01:21

Time and frequency -Domain Interpretation of Phase-lag Control

Phase-lag controllers are widely used in control systems to improve stability and reduce steady-state errors. A dimmer switch controlling the brightness of a light bulb serves as a practical example of phase-lag control, gradually adjusting the bulb's brightness. Mathematically, phase-lag control or low-pass filtering is represented when the factor 'a' is less than 1.
Phase-lag controllers do not place a pole at zero, but instead influence the steady-state error by amplifying any...
415
Conservation of Protein Domains Over Different Proteins02:26

Conservation of Protein Domains Over Different Proteins

Protein domains are small structurally independent units that are part of a single amino acid chain.  Although these domains are often structurally independent, they may rely on synergistic effects to perform their functions as part of a larger protein. Protein domains may be conserved within the same organism, as well as across different organisms.
A limited set of protein domains often duplicate and recombine during evolution. These domains can be organized in different combinations to...
14.4K