T R D Shaw

Interventional versus conservative treatment for patients with unstable angina or non-ST-elevation myocardial infarction: the British Heart Foundation RITA 3 randomised trial

BACKGROUND Current guidelines suggest that, for patients at moderate risk of death from unstable coronary-artery disease, either an interventional strategy (angiography followed by revascularisation) or a conservative strategy (ischaemia-driven or symptom-driven angiography) is appropriate. We aimed to test the hypothesis that an interventional strategy is better than a conservative strategy in such patients. METHODS We did a randomised multicentre trial of 1810 patients with non-ST-elevation acute coronary syndromes (mean age 62 years, 38% women). Patients were assigned an early intervention or conservative strategy. The antithrombin agent in both groups was enoxaparin. The co-primary endpoints were a combined rate of death, non-fatal myocardial infarction, or refractory angina at 4 months; and a combined rate of death or non-fatal myocardial infarction at 1 year. Analysis was by intention to treat. FINDINGS At 4 months, 86 (9.6%) of 895 patients in the intervention group had died or had a myocardial infarction or refractory angina, compared with 133 (14.5%) of 915 patients in the conservative group (risk ratio 0.66, 95% CI 0.51-0.85, p=0.001). This difference was mainly due to a halving of refractory angina in the intervention group. Death or myocardial infarction was similar in both treatment groups at 1 year (68 [7.6%] vs 76 [8.3%], respectively; risk ratio 0.91, 95% CI 0.67-1.25, p=0.58). Symptoms of angina were improved and use of antianginal medications significantly reduced with the interventional strategy (p<0.0001). INTERPRETATION In patients presenting with unstable coronary-artery disease, an interventional strategy is preferable to a conservative strategy, mainly because of the halving of refractory or severe angina, and with no increased risk of death or myocardial infarction.

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.

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.

Hospital Practice: STOPPING SMOKING AFTER MYOCARDIAL INFARCTION

Abstract 125 survivors of acute myocardial infarction were given a detailed explanation followed by firm advice to stop smoking. This was reinforced by written advice, and motivation was continued in a follow-up clinic. 62% were persuaded to stop, and have remained non-smokers for 1-3 years so far. By comparison, in a similar group of 85 patients, treated in the same coronary-care unit but thereafter given conventional advice and not followed up, 27·5% were non-smokers 1-3 years later.

Significance of commissural calcification on outcome of mitral balloon valvotomy

OBJECTIVE To evaluate the significance of commissural calcification, identified by transthoracic echocardiography, on the haemodynamic and symptomatic outcome of mitral balloon valvotomy. METHODS Commissural calcification was graded from 0–4 using parasternal short axis transthoracic views. The morphology of the mitral valve was also assessed using the Massachusetts General Hospital echo score. SETTING A tertiary cardiac centre in Scotland. PATIENTS 300 patients were studied, 85 retrospectively and 215 prospectively. Mean (SD) age was 59.8 (12.7) years, range 13 to 87; 30% had been judged unsuitable for surgery. Median echo score was 6.8 (3.0), range 2–16. MAIN OUTCOME MEASURES Immediate increase in mitral valve area and in New York Heart Association functional class 1–3 months after balloon valvotomy. RESULTS On univariate and multivariate analysis, commissural calcification grade was a significant predictor of achieving a mitral valve area of > 1.50 cm2 without severe mitral reflux. Its influence was greatest in patients with an echo score ⩽ 8: those with commissural calcification grade 0/1 had significantly greater improvement in valve area and symptom status than those with grade 2/3; the proportions of patients achieving a final valve area of > 1.50 cm2 were 67% and 46%, respectively (p < 0.05). In patients with an echo score of > 8, the influence of commissural calcification was smaller and not significant. CONCLUSIONS Commissural calcification as assessed by transthoracic echocardiography is a useful predictor of outcome in patients with otherwise “good” valves (echo score ⩽ 8). Calcification of one commissure or more predicts a less than 50% probability of achieving a valve area above 1.50 cm2and is an indication for valve replacement in those who are suitable for surgery.

Long term outcome of percutaneous mitral balloon valvotomy in patients aged 70 and over

OBJECTIVE To assess the immediate haemodynamic improvement and long term symptomatic benefit of percutaneous mitral balloon valvotomy in patients aged over 70 years. DESIGN Pre- and postprocedure haemodynamic data and follow up for 1 to 10 years by clinic visit or telephone contact. SETTING Tertiary referral centre in Scotland. SUBJECTS 80 patients age 70 and over who had mitral balloon dilatation: 55 were considered unsuitable for surgical treatment because of frailty or associated disease. In an additional four patients mitral dilatation was not achieved. MAIN OUTCOME MEASURES Increase in valve area after balloon dilatation and survival, freedom from valve replacement, and symptom class at follow up. RESULTS Mean (SD) valve area increased by 89% from 0.84 (0.28) to 1.59 (0.67) cm2. There was a low rate of serious complications, with only two patients having long term major sequelae. Of 55 patients unsuitable for surgical treatment, 28 (51%) were alive without valve replacement and with improvement by at least one symptom class at one year, and 14 (25%) at five years. In the 25 patients considered suitable for surgical treatment, 16 (64%) achieved this outcome at one year and nine (36%) at five years. CONCLUSIONS Percutaneous mitral balloon valvotomy is a safe and useful palliative procedure in elderly patients who are unsuitable for surgery. Balloon dilatation should also be used for elderly patients whose valve appears suitable for improvement by commissurotomy, but echo score is an imperfect predictor of haemodynamic improvement.

A Prospective Study of Left Atrial Spontaneous Echo Contrast and Thrombus in 100 Consecutive Patients Referred for Balloon Dilation of the Mitral Valve

The aim of this study was to determine the clinical, echocardiographic, and hemodynamic predictors of left atrial spontaneous echo contrast (SEC) and thrombus, respectively, in patients referred for balloon dilation of the mitral valve and to establish the relationship between the two phenomena in this group of patients. One hundred consecutive patients (mean age 57 +/- 14 years) referred for mitral balloon (Inoue) dilation were studied prospectively with transthoracic and transesophageal (83 biplane and 17 single plane) echocardiography (TEE) combined with spectral and color Doppler modalities, immediately before the procedure. TEE was repeated within 24 hours of valvotomy in the first 55 patients. All patients also underwent comprehensive left- and right-sided heart catheterization. TEE was performed successfully in 96 patients. SEC was detected in all 65 patients in atrial fibrillation and in 14 (45%) of 31 patients in sinus rhythm. Patients with SEC were significantly older (61 +/- 13 vs 45 +/- 12 years; p < 0.001) and had larger left atrial volume (98 +/- 48 vs 64 +/- 24 ml; p < 0.001), higher mitral valve echocardiographic scores (7.4 +/- 3.2 vs 5.3 +/- 2.6; p = 0.016), lower cardiac output (3.5 +/- 1.1 versus 4.6 +/- 0.9 L/min; p < 0.001), lower peak systolic pulmonary vein flow velocity (SVm) (24 +/- 12 versus 45 +/- 11 cm/sec; p < 0.001), and correspondingly lower systolic velocity-time integral (4.0 +/- 2.6 vs 7.9 +/- 2.9 cm; p < 0.001) than had patients without SEC. There were no significant associations between SEC and either mitral valve area or anticoagulant therapy. SVm and atrial fibrillation were found to be independent predictors of SEC. In patients in sinus rhythm, SVm was the only independent predictor of SEC. After mitral balloon dilation, SEC disappeared in only two of 35 patients in atrial fibrillation and in five of eight patients in sinus rhythm. Significant mitral regurgitation occurred in the two patients in atrial fibrillation. TEE detected left atrial thrombus in 14 patients. Thrombus was significantly associated with age, mitral valve area, and the severity of SEC. The latter was found to be an independent predictor of thrombus. Two patients in sinus rhythm had evidence of left atrial mechanical dysfunction. Both patients had left atrial SEC and one had thrombus in the appendage. It is concluded that SEC in patients with severe mitral stenosis is dependent on left atrial systolic function and peak systolic pulmonary vein velocity. It is not related to mitral valve area or anticoagulant therapy.(ABSTRACT TRUNCATED AT 400 WORDS)

Clinical and haemodynamic profiles of young, middle aged, and elderly patients with mitral stenosis undergoing mitral balloon valvotomy.

Objective: To compare the clinical characteristics, haemodynamic findings, and symptomatic outcome in four age groups of patients in the UK undergoing percutaneous mitral balloon valvotomy. Design: A review of patients with mitral stenosis treated by balloon dilatation. Setting: Western General Hospital, Edinburgh, a cardiac referral centre. Results: Of 405 patients who had mitral balloon valvotomy, 19 were aged under 40 years, 101 aged 40–54, 173 aged 55–69, and 112 were 70 years old or more. Medical co-morbidity and Parsonnet score for risk at surgery increased notably with age. Older patients had greater symptomatic limitation and a more severe degree of mitral stenosis, with more valve degenerative change. The incidence of atrial fibrillation, mitral reflux, left ventricular impairment, coronary artery disease, and aortic valve disease increased progressively with age. Before balloon dilatation the right ventricular systolic and left atrial pressures were similar in all age groups, but younger patients had a higher transmitral gradient and cardiac output. After balloon dilatation the younger patients achieved a greater increase in valve area. Complications of balloon valvotomy were more common in the older patients. At five years after balloon dilatation the percentages of patients in each age group who were in New York Heart Association classes I and II were 87%, 63%, 36%, and 19%, respectively. Mortality at five years was 0%, 5%, 31%, and 59%. Conclusions: Percutaneous balloon valvotomy gives a good haemodynamic and symptomatic result in patients under 55. In older patients improvement is often less pronounced and less sustained, but the procedure is a well tolerated palliative treatment for those unsuitable for surgery.

Contemporary criteria for the selection of patients for percutaneous balloon mitral valvuloplasty.

Percutaneous balloon mitral valvuloplasty is now the treatment of choice for many patients with symptomatic mitral stenosis Applications are expanding to include several categories of patients previously considered ineligible for the procedure. Commissural fusion is now recognised as the principal pathology underlying mitral stenosis, and commissural splitting underlies successful interventional treatment. Although the technique of surgical commissurotomy was first described as early as 1948,1 percutaneous commissurotomy became a feasible option with the advent of the Inoue balloon in 1984.2 Percutaneous balloon mitral valvuloplasty (PBMV) is now the treatment of choice for many patients with symptomatic mitral stenosis. Numerous large series have reported excellent short, medium, and long term outcome3–7 with a low incidence of serious complications.8 Furthermore, randomised trials comparing balloon valvuloplasty with the surgical alternatives of open or closed commissurotomy have demonstrated equivalent outcome,9,10 although patients treated using the percutaneous approach enjoy the advantages of reduced procedural morbidity and mortality and a short hospital stay. Specific advantages of the Inoue balloon in comparison with other percutaneous techniques include a lower risk of complications (particularly left ventricular perforation which is more frequent using double balloon techniques), easier manoeuvrability, its slender profile (creating a smaller defect in the interatrial septum), its self positioning characteristics, short inflation–deflation cycle, and capacity to permit gradually increasing successive balloon inflation sizes, which allow the operator to terminate the procedure when commissural splitting is achieved or when there is an increase in the severity of mitral regurgitation. Disadvantages include circumferential application of pressure during balloon inflation, occasionally resulting in paracommissural tears, especially in degenerate, calcified valves. In developing nations, the application of PBMV is frequently limited on account of the high cost of the Inoue balloon. The development of a percutaneous metallic valvulotome, which can be autoclaved after each …

Transoesophageal echocardiographic assessment of mitral valve commissural morphology predicts outcome after balloon mitral valvotomy

Objective: To investigate the value of transoesophageal echocardiography in the assessment of commissural morphology and prediction of outcome after balloon mitral valvotomy (BMV). Design: Prospective study. Setting: Tertiary cardiac referral centre. Patients: 72 consecutive patients (mean age 61.3 years, range 38–89 years) referred for BMV. Interventions: Transoesophageal echocardiography was performed immediately before BMV and the mitral commissures were scanned systematically. Anterolateral and posteromedial commissures were scored individually according to whether non-calcified fusion was absent (0), partial (1), or extensive (2). Calcified commissures usually resist splitting and scored 0. Scores for each commissure were combined giving an overall commissure score for each valve of 0–4, higher scores reflecting increased likelihood of commissural splitting. Valve anatomy was also graded by the method of Wilkins et al, which does not include commissural assessment. Main outcome measures: Patients were divided into outcome groups: A (good) and B (suboptimal). “Good” was defined as final valve area > 1.5 cm2 with a > 25% increase in area and absence of severe mitral regurgitation judged by echocardiography. Results: Valve area increased from a mean (SD) of 1.1 (0.28) cm2 to 1.8 (0.46) cm2. Commissure scores were higher in group A than in group B (p < 0.01), scores ⩾ 2 predicting a good outcome with positive and negative accuracy of 67% and 82%, respectively (p < 0.001). Commissure score was the strongest independent predictor of outcome. Conclusion: Transoesophageal echocardiographic assessment of commissural morphology predicts outcome after BMV, adding significantly to the Wilkins score.