D. Scott Gantt

Comparison of Clinical Interpretation with Visual Assessment and Quantitative Coronary Angiography in Patients Undergoing Percutaneous Coronary Intervention in Contemporary Practice: The Assessing Angiography (A2) Project

Background— Studies conducted decades ago described substantial disagreement and errors in physicians’ angiographic interpretation of coronary stenosis severity. Despite the potential implications of such findings, no large-scale efforts to measure or improve clinical interpretation were subsequently undertaken. Methods and Results— We compared clinical interpretation of stenosis severity in coronary lesions with an independent assessment using quantitative coronary angiography (QCA) in 175 randomly selected patients undergoing elective percutaneous coronary intervention at 7 US hospitals in 2011. To assess agreement, we calculated mean difference in percent diameter stenosis between clinical interpretation and QCA and a Cohen weighted &kgr; statistic. Of 216 treated lesions, median percent diameter stenosis was 80.0% (quartiles 1 and 3, 80.0% and 90.0%), with 213 (98.6%) assessed as ≥70%. Mean difference in percent diameter stenosis between clinical interpretation and QCA was 8.2±8.4%, reflecting an average higher percent diameter stenosis by clinical interpretation (P<0.001). A weighted &kgr; of 0.27 (95% confidence interval, 0.18–0.36) was found between the 2 measurements. Of 213 lesions considered ≥70% by clinical interpretation, 56 (26.3%) were <70% by QCA, although none were <50%. Differences between the 2 measurements were largest for intermediate lesions by QCA (50% to <70%), with variation existing across sites. Conclusions— Physicians tended to assess coronary lesions treated with percutaneous coronary intervention as more severe than measurements by QCA. Almost all treated lesions were ≥70% by clinical interpretation, whereas approximately one quarter were <70% by QCA. These findings suggest opportunities to improve clinical interpretation of coronary angiography.

Safety of decreasing bedrest after coronary angiography

This study was designed to assess the safety of allowing patients to ambulate after 2 hr of bedrest following coronary angiography. A total of 205 patients were randomized to either 2 or 4 hr of bedrest following hemostasis after angiography utilizing five, six, or seven French catheters. The primary endpoint was defined as bleeding requiring recompression and additional bedrest. No significant difference was demonstrated overall between the two groups with respect to rebleeding or hematoma formation when the angiogram was performed using five or six French catheters. However, the use of seven French catheters resulted in a significantly higher rebleeding rate in the 2-hr group compared to the 4-hr population. The findings of this study suggest that 2 hr of bedrest following angiography utilizing five or six French catheters is adequate to obtain hemostasis safely in the majority of patients, whereas 4 hr is suggested when seven French catheters are utilized.

Temporary coronary guidewire pacing during percutaneous coronary intervention

Temporary pacing is occasionally required during percutaneous coronary artery interventions. This can be accomplished by the insertion of a temporary transvenous pacemaker wire into the right ventricle, but there is some risk and inconvenience associated with this approach. Temporary pacing using the coronary artery guidewire was described in 1985 but is used infrequently. Using currently available equipment, we evaluated guidewire pacing in 26 patients. Guidewire pacing was successful in all patients, but not with all coronary guidewires at acceptable ventricular capture thresholds. No complications occurred from guidewire pacing. Bench testing of multiple different wires showed several with very high resistances likely unsuitable for clinical use. Temporary guidewire pacing is easily performed and should be considered as an alternative to the separate placement of a temporary transvenous pacemaker. Catheter Cardiovasc Interv 2004;61:494–500.

Assessment of anticoagulation using activated clotting times in patients receiving intravenous enoxaparin during percutaneous coronary intervention.

Enoxaparin is being used more frequently in patients undergoing percutaneous coronary intervention (PCI). In this study, we determined the effect of intravenous enoxaparin on activated clotting time (ACT) measurements in the setting of PCI. In 67 consecutive patients, either 1 mg/kg intravenous enoxaparin alone was given for anticoagulation or 0.75 mg/kg given in patients receiving eptifibatide. ACT was measured before and 5 min following enoxaparin administration. After 1 mg/kg enoxaparin (n = 22), mean ACT increased from 122 ± 22 to 199 ± 20 sec. After 0.75 mg/kg enoxaparin and eptifibatide (n = 45), mean ACT increased from 125 ± 22 to 194 ± 24 sec. The mean increase in ACT was 77 ± 26 sec in the 1 mg/kg group and 69 ± 23 sec in the 0.75 mg/kg group (both P values < 0.0001). Moreover, in a subgroup of 26 patients, there was an excellent correlation (r = 0.86) between ACTs and the ENOX test, a new point‐of‐care test for assessing enoxaparin anticoagulation. None of the patients had transient abrupt closure, thrombus formation, major bleeding, or required urgent revascularization. Intravenous enoxaparin at clinically relevant doses with and without eptifibatide increases ACT levels at 5 min in patients undergoing PCI. These data suggest the ACT may be useful in the assessment of anticoagulation by enoxaparin. Catheter Cardiovasc Interv 2004;61:52–55.

Hospital disposition and long-term follow-up of patients aged ≥80 years undergoing coronaryartery revascularization

Coronary artery revascularization by either percutaneous coronary intervention or coronary artery bypass graft surgery in patients >/=80 years of age can be accomplished with acceptable in-hospital and 2-year clinical outcomes. However, up to 20% of patients have a prolonged recovery and are unable to immediately return home. It is important that this information become part of the discussion with patients and their families so realistic expectations can be developed.

Clinical research: interventional cardiology/editorial commentCoronary intervention at hospitals without on-site cardiac surgery: are we pushing the envelope too far?*

Invasive cardiologists who lived through the early years of balloon angioplasty remember those initial terrible moments when we realized something was very wrong. The ST-segments were rising, the blood pressure was falling, and we heard our patient utter that dreadful statement, “Doc, I feel like

Comparison of Clinical Interpretation With Visual Assessment and Quantitative Coronary Angiography in Patients Undergoing Percutaneous Coronary Intervention in Contemporary Practice

Background— Studies conducted decades ago described substantial disagreement and errors in physicians’ angiographic interpretation of coronary stenosis severity. Despite the potential implications of such findings, no large-scale efforts to measure or improve clinical interpretation were subsequently undertaken. Methods and Results— We compared clinical interpretation of stenosis severity in coronary lesions with an independent assessment using quantitative coronary angiography (QCA) in 175 randomly selected patients undergoing elective percutaneous coronary intervention at 7 US hospitals in 2011. To assess agreement, we calculated mean difference in percent diameter stenosis between clinical interpretation and QCA and a Cohen weighted &kgr; statistic. Of 216 treated lesions, median percent diameter stenosis was 80.0% (quartiles 1 and 3, 80.0% and 90.0%), with 213 (98.6%) assessed as ≥70%. Mean difference in percent diameter stenosis between clinical interpretation and QCA was 8.2±8.4%, reflecting an average higher percent diameter stenosis by clinical interpretation (P<0.001). A weighted &kgr; of 0.27 (95% confidence interval, 0.18–0.36) was found between the 2 measurements. Of 213 lesions considered ≥70% by clinical interpretation, 56 (26.3%) were <70% by QCA, although none were <50%. Differences between the 2 measurements were largest for intermediate lesions by QCA (50% to <70%), with variation existing across sites. Conclusions— Physicians tended to assess coronary lesions treated with percutaneous coronary intervention as more severe than measurements by QCA. Almost all treated lesions were ≥70% by clinical interpretation, whereas approximately one quarter were <70% by QCA. These findings suggest opportunities to improve clinical interpretation of coronary angiography.

Response to Letters Regarding Article, “Comparison of Clinical Interpretation With Visual Assessment and Quantitative Coronary Angiography in Patients Undergoing Percutaneous Coronary Intervention in Contemporary Practice: The Assessing Angiography (A2) Project”

We appreciate the concerns raised by Drs Khandelwal and Kern about our recent analysis of the visual assessment of angiographic stenosis among percutaneous coronary intervention (PCI)–treated lesions in contemporary practice.1 In sum, their concerns involve the admittedly imperfect nature of quantitative coronary angiography (QCA), which they suggest should not be used as a tool for clinical assessments in the catheterization laboratory. We agree that QCA has limitations (and noted many of their points in our Discussion). In particular, we specifically acknowledged that QCA ‘as it is currently used’ does not account for many factors that should influence clinical decisions on revascularization. Nonetheless, we do believe that QCA, as an unbiased and highly reliable technique, may help quality improvement efforts by identifying (and perhaps narrowing) gaps in performance related to visual assessment. This was the overarching goal of our study, and we believe our findings strongly suggest a need to improve visual assessment. Despite several previous studies that have demonstrated deficiencies with visual assessment over the last several decades, there has been no concerted effort by the cardiology community to address extensive interobserver and intraoperator variability in the …

Comparison of Clinical Interpretation With Visual Assessment and Quantitative Coronary Angiography in Patients Undergoing Percutaneous Coronary Intervention in Contemporary PracticeClinical Perspective: The Assessing Angiography (A2) Project

Background— Studies conducted decades ago described substantial disagreement and errors in physicians’ angiographic interpretation of coronary stenosis severity. Despite the potential implications of such findings, no large-scale efforts to measure or improve clinical interpretation were subsequently undertaken. Methods and Results— We compared clinical interpretation of stenosis severity in coronary lesions with an independent assessment using quantitative coronary angiography (QCA) in 175 randomly selected patients undergoing elective percutaneous coronary intervention at 7 US hospitals in 2011. To assess agreement, we calculated mean difference in percent diameter stenosis between clinical interpretation and QCA and a Cohen weighted &kgr; statistic. Of 216 treated lesions, median percent diameter stenosis was 80.0% (quartiles 1 and 3, 80.0% and 90.0%), with 213 (98.6%) assessed as ≥70%. Mean difference in percent diameter stenosis between clinical interpretation and QCA was 8.2±8.4%, reflecting an average higher percent diameter stenosis by clinical interpretation (P<0.001). A weighted &kgr; of 0.27 (95% confidence interval, 0.18–0.36) was found between the 2 measurements. Of 213 lesions considered ≥70% by clinical interpretation, 56 (26.3%) were <70% by QCA, although none were <50%. Differences between the 2 measurements were largest for intermediate lesions by QCA (50% to <70%), with variation existing across sites. Conclusions— Physicians tended to assess coronary lesions treated with percutaneous coronary intervention as more severe than measurements by QCA. Almost all treated lesions were ≥70% by clinical interpretation, whereas approximately one quarter were <70% by QCA. These findings suggest opportunities to improve clinical interpretation of coronary angiography.