Unemployment and deprivation are associated with a poorer outcome following percutaneous coronary angioplasty.

This prospective observational study aimed to assess the impact of employment status and deprivation on quality of life 12 months after percutaneous coronary intervention (PCI). Patients completed a questionnaire at baseline and at 1 year follow-up including a health utility score (EQ-5D), symptoms and employment status. Deprivation was assessed using the Carstairs' deprivation category based on area postcodes. The majority (79.6%) of patients of working age returned to work within 12 months. Unemployment was associated with a lower quality of life (QoL) at baseline (0.49 (0.32) vs 0.61 (0.27), p=0.002) and less improvement in QoL 1 year after PCI (0.15 (0.37) vs 0.26 (0.31), p<0.012). Furthermore, unemployed patients had significantly less improvement in chest pain score (p=0.002) and breathlessness (p<0.001). Unemployed patients from the most deprived areas had lowest QoL at follow-up and least improvement in QoL at 1 year. Unemployment and deprivation are associated with poorer outcomes following PCI.

Effects of changing clinical practice on costs and outcomes of percutaneous coronary intervention between 1998 and 2002.

AIM: To assess the effect of changing clinical practice on the costs and outcomes of percutaneous coronary intervention (PCI) between 1998 and 2002. SETTING: Two tertiary interventional centres. PATIENTS: Consecutive patients undergoing PCI over a 12-month period between 1998 and 2002. DESIGN: Comparative observational study of costs and 12-month clinical outcomes of consecutive PCI procedures in 1998 (n = 1047) and 2002 (n = 1346). Clinical data were recorded in the Scottish PCI register. Repeat PCI, coronary artery bypass graft and mortality were obtained by record linkage. Costs of equipment were calculated using a computerised bar-code system and standard National Health Service reference costs. RESULTS: Between 1998 and 2002, the use of bare metal stents increased from 44% to 81%, and the use of glycoprotein IIB/IIIA inhibitors increased from 0% to 14% of cases. During this time, a significant reduction was observed in repeat target-vessel PCI (from 8.4% to 5.1%, p = 0.001), any repeat PCI (from 11.7% to 9.2%, p = 0.05) and any repeat revascularisation (from 15.1% to 11.3%, p = 0.009) within 12 months. Significantly higher cost per case in 2002 compared with 1998 (mean (standard deviation) 2311 pounds (1158) v 1785 pounds (907), p<0.001) was mainly due to increased contribution from bed-day costs in 2002 (45.0% (16.3%) v 26.2% (12.6%), p = 0.01) associated with non-elective cases spending significantly longer in hospital (6.22 (4.3) v 4.6 (4.3) days, p = 0.01). CONCLUSIONS: Greater use of stents and glycoprotein IIb/IIIa inhibitors between 1998 and 2002 has been accompanied by a marked reduction in the need for repeat revascularisation. Longer duration of hospital stay for non-elective cases is mainly responsible for increasing costs. Strategies to reduce the length of stay could considerably reduce the costs of PCI.

Influence of socioeconomic status on clinical outcomes and quality of life after percutaneous coronary intervention.

OBJECTIVES: To determine whether socioeconomic status (SES) influences clinical outcomes and quality of life after percutaneous coronary intervention (PCI). DESIGN: Prospective observational study. SETTING: Two interventional cardiac centres. PARTICIPANTS: 1346 consecutive patients undergoing PCI over a 12-month period. OUTCOMES: Self reported health-related quality of life (HRQoL; EuroQol-5 Dimensions (EQ-5D); EuroQol Visual Analogue Scale (EQ-VAS)), repeat angiography, revascularisation, hospital admission, myocardial infarction and death within 12 months, by SES derived using postal address code. MAIN RESULTS: No significant differences were found between patients with high and low SES in the occurrence of repeat angiography (p = 0.55), repeat revascularisation (PCI, p = 0.81, CAEG, p = 0.27), total cardiac hospitalisation (p = 0.10), myocardial infarction (p = 0.97) or death 12 months after PCI (p = 0.88). Non-procedure-related readmissions were higher in patients with low SES (18.6% v 13.7%; p = 0.025). After adjustment for confounding factors, patients with low SES had lower HRQoL scores at baseline (95% CI for difference 0.01 to 0.14; p = 0.003) and at 12 months (95% CI 0.07 to 0.17; p<0.001) compared with those with high SES. CONCLUSIONS: Clinical outcomes were similar for patients in different SES groups. Patients with low SES had considerably more non-procedure-related readmissions and lower quality-of-life scores. Future studies on HRQoL after coronary revascularisation should take account of these important differences related to SES.

Hospital volume of throughput and periprocedural and medium-term adverse events after percutaneous coronary intervention: retrospective cohort study of all 17,417 procedures undertaken in Scotland, 1997-2003.

OBJECTIVE: To determine whether percutaneous coronary intervention (PCI) hospital volume of throughput is associated with periprocedural and medium-term events, and whether any associations are independent of differences in case mix. DESIGN: Retrospective cohort study of all PCIs undertaken in Scottish National Health Service hospitals over a six-year period. METHODS: All PCIs in Scotland during 1997-2003 were examined. Linkage to administrative databases identified events over two years' follow up. The risk of events by hospital volume at 30 days and two years was compared by using logistic regression and Cox proportional hazards models. RESULTS: Of the 17,417 PCIs, 4900 (28%) were in low-volume hospitals and 3242 (19%) in high-volume hospitals. After adjustment for case mix, there were no significant differences in risk of death or myocardial infarction. Patients treated in high-volume hospitals were less likely to require emergency surgery (adjusted odds ratio 0.18, 95% confidence interval (CI) 0.07 to 0.54, p = 0.002). Over two years, patients in high-volume hospitals were less likely to undergo surgery (adjusted hazard ratio 0.52, 95% CI 0.35 to 0.75, p = 0.001), but this was offset by an increased likelihood of further PCI. There was no net difference in coronary revascularisation or in overall events. CONCLUSION: Death and myocardial infarction were infrequent complications of PCI and did not differ significantly by volume. Emergency surgery was less common in high-volume hospitals. Over two years, patients treated in high-volume centres were as likely to undergo some form of revascularisation but less likely to undergo surgery.

Variations in clinical decision-making between cardiologists and cardiac surgeons; a case for management by multidisciplinary teams?

OBJECTIVE: To assess variations in decisions to revascularise patients with coronary heart disease between general cardiologists, interventional cardiologists and cardiac surgeons DESIGN: Six cases of coronary heart disease were presented at an open meeting in a standard format including clinical details which might influence the decision to revascularise. Clinicians (n = 53) were then asked to vote using an anonymous electronic system for one of 5 treatment options: medical, surgical (CABG), percutaneous coronary intervention (PCI) or initially medical proceeding to revascularisation if symptoms dictated. Each case was then discussed in an open forum following which clinicians were asked to revote. Differences in treatment preference were compared by chi squared test and agreement between groups and between voting rounds compared using Kappa. RESULTS: Surgeons were more likely to choose surgery as a form of treatment (p = 0.034) while interventional cardiologists were more likely to choose PCI (p = 0.056). There were no significant differences between non-interventional and interventional cardiologists (p = 0.13) in their choice of treatment. There was poor agreement between all clinicians in the first round of voting (Kappa 0.26) but this improved to a moderate level of agreement after open discussion for the second vote (Kappa 0.44). The level of agreement among surgeons (0.15) was less than that for cardiologists (0.34) in Round 1, but was similar in Round 2 (0.45 and 0.45 respectively). CONCLUSION: In this case series, there was poor agreement between cardiac clinical specialists in the choice of treatment offered to patients. Open discussion appeared to improve agreement. These results would support the need for decisions to revascularise to be made by a multidisciplinary panel.

Contemporary management of acute coronary syndromes: does the practice match the evidence? The global registry of acute coronary events (GRACE).

OBJECTIVE: To determine to what extent evidence based guidelines are followed in the management of acute coronary syndromes (ACS) in the UK, elsewhere in Europe, and multinationally, and what the outcomes are. DESIGN: Multinational, prospective, observational registry (GRACE, global registry of acute coronary events) with six months' follow up. SETTING: Patients presenting to a cluster of hospitals. The study was designed to collect data representative of the full spectrum of ACS in specific geographic populations. PATIENTS: Patients admitted with a working diagnosis of unstable angina or suspected myocardial infarction (MI). MAIN OUTCOME MEASURES: Death during hospitalisation and at six months' follow up (adjusted for baseline risks). RESULTS: In ST elevation MI, reperfusion was applied more often in the UK (71%) than in Europe (65%) and multinationally (59%) (p < 0.01). However, this was almost entirely by lytic treatment, in contrast with elsewhere (primary percutaneous coronary intervention 1%, 29%, 16%, respectively). Statins were applied more frequently in the UK for all classes of patients with ACS (p < 0.0001). In contrast there was lower use of revascularisation procedures in non-ST MI (20% v 37% v 28%, respectively) and glycoprotein IIb/IIIa antagonists (6% v 25% v 26%, respectively). In-hospital death rates, adjusted for baseline risk, were not significantly different but six month death rates were higher in the UK for ST elevation MI (7.2% UK, 4.3% Europe, 5.3% multinationally; p < 0.0001) and non-ST elevation MI (7.5%, 6.2%, and 6.7%, respectively; p = 0.012, UK v Europe). CONCLUSIONS: Current management of ACS in the UK more closely follows the recommendations of the National Service Framework than British or European guidelines. Differences in practice may account for the observed higher event rates in the UK after hospital discharge.

Comparing performance between coronary intervention centres requires detailed case-mix adjusted analysis.

This study compares 12 month clinical outcomes and procedural costs at two interventional centres with significant differences in crude mortality and revascularization outcomes between 1997 and 1998. Percutaneous coronary intervention (PCI) registry data on 1046 consecutive patients treated contemporaneously at two university centres were linked to hospital discharge and death data to provide 12 month follow-up information on survival and repeat revascularization. Costs were determined by detailed analysis of equipment use, length of stay and staff from 100 contemporary cases at each centre to derive a procedural cost model. This model was then applied retrospectively to estimate cost per procedure. Stents were used more frequently at one centre (56 versus 26 per cent, chi(2) test, p < 0.001) resulting in greater procedural cost [mean (SE), pounds sterling 1970 (34) versus pounds sterling 1521 (39), t-test, p < 0.001). One year repeat target vessel PCI was significantly greater at the centre using more stents (10.3 versus 5.6 per cent, chi(2) test, p = 0.005) and the need for any repeat revascularization (PCI or coronary artery by-pass surgery) was also significantly greater at this centre (18.4 versus 10.8 per cent, chi(2) test, p < 0.001). Cox regression revealed that after correction for case-mix the difference in the need for repeat target vessel PCI between the two centres was no longer significant (p = 0.15). In the two centres studied, crude differences in cost per case, mortality and the need for revascularization were largely accounted for by significant differences in case-mix. Comparison of outcomes and costs between centres should not be published without careful adjustment for differences in case-mix.

Comparison of survival following coronary artery bypass grafting vs. percutaneous coronary intervention in diabetic and non-diabetic patients: retrospective cohort study of 6320 procedures.

AIM: To determine whether mortality following percutaneous coronary intervention vs. coronary bypass grafting varies according to whether or not patients have diabetes. METHODS: We used the Scottish Coronary Revascularization Register to identify all patients undergoing revascularization in Scottish NHS hospitals since 1997. We excluded single-vessel disease, left main stem stenosis, and bypass grafting performed at the same time as other operations. We used death certificate data from the Registrar General to identify all subsequent deaths. RESULTS: Of the 6320 eligible procedures, 5042 (80%) were bypass grafts and 1278 (20%) angioplasties. Overall 831 (13%) patients had diabetes with no significant difference by procedure (13% vs. 12%). A total of 382 deaths occurred over a mean follow-up of 2.3 years. Diabetic patients had a poorer prognosis following both surgery (adjusted hazards ratio (HR) 1.43, 95% confidence interval (CI) 1.08, 1.89) and percutaneous intervention (adjusted HR 2.58, 95% CI 1.43, 4.63). Among non-diabetic patients, no significant differences in mortality were detected between the two procedures. Among diabetic patients, no significant difference was detected in those with two-vessel disease. In those with impaired left ventricular function and triple-vessel disease, angioplasty was associated with a significantly higher risk of death (adjusted HR 3.58, 95% CI 1.40, 9.19). CONCLUSIONS: This is the first study to demonstrate statistically significant results that support the BARI trial findings. Our study demonstrated a significant difference for triple-vessel disease but not two-vessel disease. The former may be due to incomplete revascularization using percutaneous intervention. Our results require corroboration from randomized trials.

Outcomes following coronary artery bypass grafting and percutaneous transluminal coronary angioplasty in the stent era: a prospective study of all 9890 consecutive patients operated on in Scotland over a two year period.

OBJECTIVE: To determine current outcomes of percutaneous transluminal coronary angioplasty (PTCA) and coronary artery bypass grafting (CABG). DESIGN: The Scottish coronary revascularisation register provided prospectively collected data on case mix and in-hospital complications for all revascularisation procedures between April 1997 and March 1999 (4775 PTCA; 5115 CABG). Linkage to routine hospital discharge and death data provided follow up information on survival and repeat revascularisation. RESULTS: Stents were used in 51% of PTCA procedures. CABG patients were older, had more severe coronary disease, and had greater comorbidity. PTCA was more likely to be undertaken as an urgent or emergency procedure. Perioperative death and urgent surgery followed 0.3% and 0.6% of PTCA procedures, respectively. Case fatality rates were higher following CABG, with 6.7% dead within two years compared with 3.4% following PTCA. PTCA was more often followed by readmission for ischaemic heart disease, repeat angiography, or revascularisation: 22.8% of patients had repeat revascularisation within two years, compared with 1.8% following CABG. CONCLUSIONS: The severity of coronary heart disease was greater than in previously published registry studies and randomised trials. Despite this, overall survival figures were comparable and repeat revascularisation rates lower, particularly following PTCA. Perioperative death and urgent surgery following PTCA were also lower. These favourable outcomes may be attributable, in part, to increased use of bail out and elective stenting.

Diltiazem in acute myocardial infarction treated with thrombolytic agents: a randomised placebo-controlled trial. Incomplete Infarction Trial of European Research Collaborators Evaluating Prognosis post-Thrombolysis (INTERCEPT)

BACKGROUND: Diltiazem reduces non-fatal reinfarction and refractory ischaemia after non-Q-wave myocardial infarction, an acute coronary syndrome similar to the incomplete infarction that occurs after successful reperfusion. We postulated that this agent would reduce cardiac events in patients after acute myocardial infarction treated initially with thrombolytic agents-a clinical application previously unexplored with heart-rate-lowering calcium antagonists. METHODS: A prospective, randomised, double-blind, sequential trial was done in 874 patients with acute myocardial infarction, but without congestive heart failure, who first received thrombolytic agents. Patients received either 300 mg oral diltiazem once daily, or placebo, initiated within 36-96 h of infarct onset, and given for up to 6 months. The trial primary endpoint was the cumulative first event rate of cardiac death, non-fatal reinfarction, or refractory ischaemia. Additional prespecified endpoints included several composites of non-fatal cardiac events (non-fatal reinfarction combined with refractory ischaemia, all recurrent ischaemia, or the need for myocardial revascularisation). The diagnosis of ischaemia, whether refractory or recurrent, and the need for myocardial revascularisation, was always based on objective electrocardiographical evidence of ischaemia, either at rest or on exertion. RESULTS: For the trial primary endpoint, 131 events occurred in the 444 placebo patients and 97 events in the 430 diltiazem patients (hazard ratio 0.79; 95% CI, 0.61-1.02; p=0.07). For non-fatal cardiac events, diltiazem treatment was associated with a relative decrease (0.76; 0.58-1.00) in the combined event rate of non-fatal reinfarction and refractory ischaemia. There was a similar decrease in the composite non-fatal endpoints of non-fatal reinfarction combined with all recurrent ischaemia (0.80; 0.64-1.00) and non-fatal reinfarction combined with the need for myocardial revascularisation (0.67; 0.46-0.96). The need for myocardial revascularisation alone was significantly reduced by 42% (0.61; 0.39-0.96). No major safety issues were encountered. CONCLUSIONS: Diltiazem did not reduce the cumulative occurrence of cardiac death, non-fatal reinfarction, or refractory ischaemia during a 6-month follow-up, but did reduce all composite endpoints of non-fatal cardiac events, especially the need for myocardial revascularisation.

Normalisation of abnormal coronary fractional flow reserve associated with myocardial bridging using an intracoronary stent.

Although intracoronary stenting procedures have been advocated for the successful treatment of myocardial ischaemia associated with myocardial bridging, the physiological rationale for this approach remains unexplored. The case of a 70 year old man with symptoms of cardiac ischaemia associated with a left anterior descending coronary artery bridge is described, where use of an intracoronary stent abolished the angiographic abnormalities and also restituted pronounced abnormalities of coronary fractional flow reserve.

In-hospital resource utilization in coronary angioplasty: the impact of increased coronary stenting rates and antiplatelet therapy.

BACKGROUND: The technique of coronary stenting has evolved over recent years, with improved stent technology and effective antiplatelet therapies to prevent stent thrombosis. In Europe, reductions in stent and equipment costs have resulted from increased market competition. The impact of these changes on the in-hospital procedural cost of percutaneous coronary intervention (PCI) in the current clinical setting is not known. METHODS: We compared the initial equipment and pharmaceutical costs of one hundred consecutive, unselected patients undergoing PCI in 1998 to a similar population who underwent PCI in 1994. RESULTS: Similar patient characteristics were noted, yet more complex disease (multivessel, AHA type B2/C lesions) was treated in the 1998 population. The stent utilization rate (83% vs 15%, p < 0.0001) and use of intravenous and/or oral antiplatelet therapy (abciximab, ticlopidine) (64% vs 4%, p < 0.0001) was higher in 1998. Similar angiographic success was achieved in each group with low complication rates. Mean hospital stay was reduced in the 1998 group (2.6 +/- 2.8 vs 4.3 +/- 3.8 days, p < 0.001). Repeat PCI was required more frequently in the 1994 population (26% vs 9%, p < 0.001). Overall there was no significant difference in the mean equipment cost between the two groups ( pound 1551 vs pound 1422, p=ns). CONCLUSION: Despite the widespread use of coronary stenting and antiplatelet therapies there appears to be no difference in current in-hospital equipment costs for PCI compared to 1994. Improved clinical outcomes in the 1998 population imply that stenting is a cost-effective therapy.

Outcome from a rapid-assessment chest pain clinic.

Chest pain accounts for much of the rising numbers of emergency admissions, but in-patient assessment is not necessarily the best way of dealing with these patients. We ran a 'rapid-assessment chest pain clinic' to provide an alternative route of assessment, and audited its outcome. General practitioners referred patients with recent-onset chest pain, increasing chest pain, chest pain at rest, or other chest pain of concern, on the understanding that they would be seen within 24 h. During 8 1/2 months, 334 patients were referred and 317 patients were seen, most of whom had exercise electrocardiography. A median of 6 months later, 278 patients were personally contacted to determine outcome. Of these, 18% had been admitted immediately with acute coronary syndromes, and 49% had been diagnosed as non-coronary chest pain (none of whom subsequently infarcted or died). Continuing symptoms were infrequent, and satisfaction was high, although 13% of patients had been revascularized. A significant number of patients required immediate admission and/or ultimate revascularization, but many more did not. The majority of these patients had non-coronary chest pain, and this diagnosis was substantiated by their excellent outcome and (in some cases) by further investigation.

Characterisation of coronary atherosclerotic morphology by spectral analysis of radiofrequency signal: in vitro intravascular ultrasound study with histological and radiological validation.

OBJECTIVE: To determine whether spectral analysis of unprocessed radiofrequency (RF) signal offers advantages over standard videodensitometric analysis in identifying the morphology of coronary atherosclerotic plaques. METHODS: 97 regions of interest (ROI) were imaged at 30 MHz from postmortem, pressure perfused (80 mm Hg) coronary arteries in saline baths. RF data were digitised at 250 MHz. Two different sizes of ROI were identified from scan converted images, and relative amplitudes of different frequency components were analysed from raw data. Normalised spectra was used to calculate spectral slope (dB/MHz), y-axis intercept (dB), mean power (dB), and maximum power (dB) over a given bandwidth (17-42 MHz). RF images were constructed and compared with comparative histology derived from microscopy and radiological techniques in three dimensions. RESULTS: Mean power was similar from dense fibrotic tissue and heavy calcium, but spectral slope was steeper in heavy calcium (-0.45 (0.1)) than in dense fibrotic tissue (-0.31 (0.1)), and maximum power was higher for heavy calcium (-7.7 (2.0)) than for dense fibrotic tissue (-10.2 (3.9)). Maximum power was significantly higher in heavy calcium (-7.7 (2.0) dB) and dense fibrotic tissue (-10.2 (3.9) dB) than in microcalcification (-13.9 (3.8) dB). Y-axis intercept was higher in microcalcification (-5.8 (1.1) dB) than in moderately fibrotic tissue (-11.9 (2.0) dB). Moderate and dense fibrotic tissue were discriminated with mean power: moderate -20.2 (1.1) dB, dense -14.7 (3.7) dB; and y-axis intercept: moderate -11.9 (2.0) dB, dense -5.5 (5.4) dB. Different densities of fibrosis, loose, moderate, and dense, were discriminated with both y-axis intercept, spectral slope, and mean power. Lipid could be differentiated from other types of plaque tissue on the basis of spectral slope, lipid -0.17 (0.08). Also y-axis intercept from lipid (-17.6 (3.9)) differed significantly from moderately fibrotic tissue, dense fibrotic tissue, microcalcification, and heavy calcium. No significant differences in any of the measured parameters were seen between the results obtained from small and large ROIs. CONCLUSION: Frequency based spectral analysis of unprocessed ultrasound signal may lead to accurate identification of atherosclerotic plaque morphology.

Dihydropyrancarboxamides related to zanamivir: a new series of inhibitors of influenza virus sialidases. 1. Discovery, synthesis, biological activity, and structure-activity relationships of 4-guanidino- and 4-amino-4H-pyran-6-carboxamides.

4-Amino- and 4-guanidino-4H-pyran-6-carboxamides 4 and 5 related to zanamivir (GG167) are a new class of inhibitors of influenza virus sialidases. Structure--activity studies reveal that, in general, secondary amides are weak inhibitors of both influenza A and B viral sialidases. However, tertiary amides, which contain one or more small alkyl groups, show much greater inhibitory activity, particularly against the influenza A virus enzyme. The sialidase inhibitory activities of these compounds correlate well with their in vitro antiviral efficacy, and several of the most potent analogues displayed useful antiviral activity in vivo when evaluated in a mouse model of influenza A virus infection. Carboxamides which were highly active sialidase inhibitors in vitro also showed good antiviral activity in the mouse efficacy model of influenza A infection when administered intranasally but displayed modest activity when delivered by the intraperitoneal route.

Differences in myocardial velocity gradient measured throughout the cardiac cycle in patients with hypertrophic cardiomyopathy, athletes and patients with left ventricular hypertrophy due to hypertension.

OBJECTIVES: We sought to compare the myocardial velocity gradient (MVG) measured across the left ventricular (LV) posterior wall during the cardiac cycle between patients with hypertrophic cardiomyopathy (HCM), athletes and patients with LV hypertrophy due to systemic hypertension and to determine whether it might be used to discriminate these groups. BACKGROUND: The MVG is a new ultrasound variable, based on the color Doppler technique, that quantifies the spatial distribution of transmyocardial velocities. METHODS: A cohort of 158 subjects was subdivided by age into two groups: Group I (mean [+/-SD] 30 +/- 7 years) and Group II (58 +/- 8 years). Within each group there were three categories of subjects: Group Ia consisted of patients with HCM (n = 25), Group Ib consisted of athletes (n = 21), and Group Ic consisted of normal subjects; Group IIa consisted of patients with HCM (n = 19), Group IIb consisted of hypertensive patients (n = 27), and Group IIc consisted of normal subjects (n = 33). RESULTS: The MVG (mean [+/-SD] s-1) measured in systole was lower (p < 0.01) in patients with HCM (Group Ia 3.2 +/- 1.1; Group IIa 2.9 +/- 1.2) compared with athletes (Group Ib 4.6 +/- 1.1), hypertensive patients (Group IIb 4.2 +/- 1.8) and normal subjects (Group Ic 4.4 +/- 0.8; Group IIc 4.8 +/- 0.8). In early diastole, the MVG was lower (p < 0.05) in patients with HCM (Group Ia 3.7 +/- 1.5; Group IIa 2.6 +/- 0.9) than in athletes (Group Ib 9.9 +/- 1.9) and normal subjects (Group Ic 9.2 +/- 2.0; Group IIc 3.6 +/- 1.5), but not hypertensive patients (Group IIb 3.3 +/- 1.3). In late diastole, the MVG in patients with HCM (Group Ia 1.3 +/- 0.8; Group IIa 1.4 +/- 0.8) was lower (p < 0.01) than that in hypertensive patients (Group IIb 4.3 +/- 1.7) and normal subjects (Group IIc 3.8 +/- 0.9). An MVG < or = 7 s-1, as a single diagnostic approach, differentiated accurately (0.96 positive and 0.94 negative predictive value) between patients with HCM and athletes when the measurements were taken during early diastole. CONCLUSIONS: In both age groups, the MVG was lower in both systole and diastole in patients with HCM than in athletes, hypertensive patients or normal subjects. The MVG measured in early diastole in a group of subjects 18 to 45 years old would appear to be an accurate variable used to discriminate between HCM and hypertrophy in athletes.

Analysis of reproducibility of reference lumen quantitation with intravascular ultrasound in stented coronary arteries.

Intravascular ultrasound is widely used to guide coronary stent implantation. The key quantitative criterion for successful implantation is the demonstration of adequate expansion of the stented lumen relative to that of the adjacent reference vessel segments. In this study we aimed to establish the reproducibility of intravascular ultrasound measurements of the reference segments in lesions undergoing coronary stenting. Measurements of the reference segment lumen dimensions warn made in a blinded fashion by two experienced observers, and reproducibility was assessed by calculating the mean difference and standard deviation of the paired measurements. The unselected intraobserver random variability of the mean reference lumen area measured 0.6 mm2. The interobserver random variability was 0.94 mm2. The intraobserver and interobserver variability of minimum lumen area within the stent was smaller, measuring 0.30 mm2 and 0.52 mm2, respectively. There was 91% intraobserver agreement, and 75% interobserver agreement, in identifying adequate stent expansion as defined by a stent-to-mean reference lumen area ratio of > 0.8. The potentially significant level of variability inherent in selecting and measuring the reference segments, and its impact on clinical decision-making, should be remembered when this method of assessing the acute quantitative outcome of stent implantation is applied.