Diagnostic accuracy of combined dipyridamole stress perfusion and delayed enhancement cardiovascular magnetic resonance imaging for detection of coronary artery disease

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Background: The diagnosis of coronary artery disease (CAD) is one of the most common clinical issues that face medical practitioners. Myocardial ischemia can be noninvasively assessed with cardiovascular magnetic resonance imaging (CMRI), which has become an emerging modality. Objective: Determine the accuracy of dipyridamole stress CMRI by using stress and rest perfusion combined with delayed enhancement imaging for detecting CAD. Methods: Thirty-nine patients (24 men, 15 women; mean age 64±11.4 years) who had experienced prior myocardial infarction or had suspected CAD were enrolled. Dipyridamole stress CMRI with subsequent coronary angiography was performed within a mean time interval of 16 days (range: 1-30 days). The dipyridamole stress CMR protocol included stress and rest perfusion followed by delayed enhancement imaging. Per-vessel analysis was done according to 17-segment model recommendation by the American Heart Association. Results: Coronary angiography depicted significant coronary artery stenosis (>70% stenosis of major epicardial artery) in 26 patients (55 coronary arteries). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the combined stress and rest perfusion with delayed enhancement imaging for detection of significant coronary artery stenosis were 76-96%, 79-96%, 87-93%, 83-96%, and 85-95%, in left anterior descending, left circumflex, and right coronary arteries, respectively. Without delayed enhancement imaging, stress and rest perfusion produced slightly lower sensitivity (69-92%), specificity (73-96%), positive predictive value (79-93%), negative predictive value (80-92%), and accuracy (79-92%). Conclusion: Dipyridamole stress CMRI combined with delayed enhancement imaging yielded high diagnostic accuracy for the detection of coronary artery disease. This modality allows the clinical application for detection of CAD in selected group of patients.

Safety and acceptable initial outcomes of reused balloon catheters for percutaneous transluminal coronary angioplasty.

OBJECTIVES: This study was conducted to compare the safety and initial outcomes applying reused balloon (RB) catheters with those of attained new balloon (NB) catheters when performing percutaneous transluminal coronary angioplasty. BACKGROUND: Recently, PTCA procedures have been used increasingly for the treatment of patients with coronary heart disease. In the era of national economic constraint, reused balloon catheters will reduce the cost of expensive, imported coronary angioplasty devices. Hence, data concerning the safety and success rate of RB catheters compared with NB catheters are urgently required. METHODS: Prospective comparative study between reused and new balloon catheters for coronary angioplasty. Data forms were completed after each procedure and before the patient was discharged after an 18-month period. RESULTS: From July 1996 to December 1997, 221 cases (121-RB, 100-NB) were enrolled. Mean age, ejection fraction, diseased vessel and lesion characteristics were similar in both groups. The number of lesions was much higher performed in the RB than in the NB group (1.7 +/- 0.9 vs 1.4 +/- 0.8, p = 0.02). The RB group had more cases of acute myocardial infarction than the NB group (7.4% vs 1%, p = 0.003), however, the angiographic and case success rate were the same (99.5% vs 97.9% and 98.3% vs 97% respectively). Major adverse cardiac events in RB amounted to 1.7 per cent and for NB to 1.0 per cent (p = ns). The total amount of balloons used in RB was much higher than in the NB group (1.5 +/- 0.6 vs 1.1 +/- 0.3, p = <0.0001). There were neither infection nor positive blood cultures in either group. CONCLUSIONS: Reused balloon catheters can be safely used for percutaneous transluminal coronary angioplasty with a high success rate. The total cost of angioplasty can be reduced without a decline in efficacy.

Percutaneous transluminal coronary angioplasty in King Chulalongkorn Memorial Hospital: a four-year experience.

From January 1993 to December 1996, 461 cases (743 lesions) of percutaneous transluminal coronary angioplasty (PTCA) were performed at King Chulalongkorn Memorial Hospital. Seventy eight per cent of the patients were male. Mean age was 61.1 +/- 9.6 yrs and mean ejection fraction was 0.59 +/- 0.18. The indications for PTCA were chronic stable angina (53%), post myocardial infarction (MI) angina (26.6%), unstable angina (17.4%) and acute MI (3%). Emergency PTCA was performed on 15 cases with 5 patients in cardiogenic shock. Fifty four per cent of the cases were performed in single vessel disease, 33 per cent in double vessel disease and 13 per cent in tripple vessel disease. The vessels dilated were the left anterior descending artery (44.2%), right coronary artery (27.8%), left circumflex artery (26.7%), left main (0.9%) and saphenous vein graft (0.4%). Mean balloon size was 2.48 mm. The overall success rate of PTCA, defined as residual diameter stenosis less than 50 per cent, was 91.5 per cent. In addition to PTCA, 123 stent implantations with mean stent size 2.98 mm and 15 rotational athrectomy were done in 114 cases. Complications of PTCA occurred in 32 cases (6.9%). Ten patients (2.2%) had abrupt closure, 1 of these needed emergency coronary bypass graft surgery (CABG). One patient (0.2%) had cerebral embolism with minor residual neurological deficit. One patient (0.2%) had toe gangrene which eventually needed amputation. One patient (0.2%) who presented with acute extensive anterior wall MI and failure of thrombolytic therapy died 8 hours after successful PTCA due to refractory cardiogenic shock. In the patients who also had stent implantation, there were 6 stent misplacements: 3 in the right femoral artery without any complication, 2 were misplacements in the coronary system and 1 dislodged in LM necessitating emergency CABG. CONCLUSION: PTCA is the coronary interventional procedure that can be performed with a high success rate and minimal complications.

The first 100 cases of intracoronary stent implantation in cardiac center, King Chulalongkorn Memorial Hospital.

At King Chulalongkorn Memorial Hospital from July 1994 to December 1996, 123 stents were implanted in 75 males and 25 females. Average age of the patients was 61.3 +/- 9.6 years. Fifty-five per cent of the cases were performed in stable angina, 26 per cent in post myocardial infarction angina. 17 per cent in unstable angina and 2 per cent in acute myocardial infarction. Seventy stents were implanted in the left anterior descending artery, 25 in the left circumflex artery, 27 in the right coronary artery and one stent in the left main. The indications for stent implantation were abrupt closure in thirteen sites, mild dissection in 58, suboptimal dilatation in 19, restenosis in 23 and de novo in 10. Mean size of the stents was 2.99 +/- 0.49 mm and mean inflation pressure was 11.9 atmosphere. Palmaz-Schatz stent was the most commonly used (53.6%) followed by AVE Microstent II (42.3%). There were 3 stents loss in the right femoral artery without any complications. Two stents were misplaced, one stent dislodged in the left main and needed emergency coronary bypass graft surgery. Two patients developed acute stent thrombosis and were successfully reopened with intracoronary urokinase. No patient had major bleeding complication, subacute thrombosis, acute myocardial infarction or death. CONCLUSION: Stent implantation can be performed rather safely with a high success rate and minimal complications.