Radiocontrast-induced nephropathy (CIN) is one of the most serious complications of percutaneous coronary interventions (PCI). The prevention of PCI-related CIN for chronic kidney disease (CKD) patients has not been established yet. The intravascular ultrasound (IVUS) is commonly used as an imaging device during PCI. We performed IVUS-guided PCI while only using fluoroscopic imaging and without administering any routine contrast dye injection during the procedures. All patients underwent a baseline coronary angiography prior to the elective PCI. During the PCI, all the following procedures were done with X-ray fluoroscopic imaging without or with a minimized contrast dye injection: the engagement of the guiding catheter, insertion of the coronary guidewire, insertion of the IVUS catheter, the stent deployment and the post-dilatation. The diameter and the length of the balloon and the stent were determined according to the pre-procedural IVUS findings, and the end point of the stent dilatation was also judged according to the acquired minimal cross-sectional area of the stent. Here we report our findings from two cases representative of IVUS-guided minimum contrast PCI in which the volumes of contrast dye during the procedure were 5 and 4 ml, respectively. No CIN occurred after either procedure. The IVUS-guided minimum contrast PCI could be a promising option for the prevention of CIN after PCI.
Background:
Immediate and accurate differential diagnosis is critically important for the patients who present acute onset of chest and/or back pain. We have noticed that regions of decreased contrast enhancement existed within the myocardial wall of the patients with acute coronary syndrome (ACS) on conventional computed tomography (CT) images, performed to differentiate other acute thoracic diseases (e.g. aortic dissection, pulmonary embolism). This study was designed to utilize these features for the differential diagnosis of ACS.
Methods:
The study population consisted of 95 consecutive patients who required enhanced CT for the differential diagnosis of acute chest discomfort at the emergency room. Using the representative apical four-chamber view, the left ventricular (LV) wall was divided into the following 6 segments: 1) basal septum, 2) mid septum, 3) apex, 4) mid lateral, 5) basal lateral and 6) basal posterior. A CT number was measured at each segment, and was then fitted into either of the following formula to calculate a segmental perfusion abnormality (SPA) index based on the existence of visually-apparent low density segments (VALDS): 1) In case of VALDS presence: average CT numbers of VALDS/average CT number of the rest normal segments × 100 (%), 2) in case of VALDS absence: the minimum CT number/average CT number of the rest 5 segments × 100 (%). The SPA index was compared between the two groups, one with ACS and another without ACS, both confirmed by coronary angiography.
Results:
Forty-five patients (47.4%) were eventually diagnosed as ACS by coronary angiography. Importantly, the SPA index was significantly smaller in the ACS group compared to the non ACS group (48.7±17.2% vs 85.5 ± 7.1%, p<0.0001). The standard receiver operating characteristic curve indicated that an optimal threshold of the SPA index is estimated to be 65%, with an achievement of high diagnostic accuracy (sensitivity: 86.7%, specificity: 98.0%, positive predictive value: 97.5%, and negative predictive value: 89.0%).
Conclusions:
The SPA index, a novel CT-based diagnostic approach for the non-invasive visualization of the ischemic LV wall, is confirmed to be easy and accurate method to differentiate ACS among the various patients who present acute chest or back pain.
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