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L M Shapiro

Publications and source records attributed to L M Shapiro.

At least 55 records · Page 3Linked to original sources
PubMed1997

Mitral valve surgery in the elderly.

BACKGROUND AND AIMS OF THE STUDY: Previous studies have shown that outcome from mitral valve surgery is poorer in the elderly. However, such studies did not distinguish between age itself, age-associated factors and interactions between age and other factors. We aimed to examine the relative influences of age and these other factors on outcome. METHODS: We compared outcomes from mitral valve repair or replacement in 190 elderly (> or = 70 years) and 424 younger (< 70 years) consecutive adult patients. RESULTS: At baseline, the elderly had more (p > 0.05) degenerative mitral regurgitation, coronary artery disease, left ventricular impairment, New York Heart Association (NYHA) class III or IV symptoms, bioprosthetic replacement and mitral valve repair. Operative mortality rate was low both in elderly (7/190 patients, 3.7%) and younger patients (15/424 patients, 3.5%, NS). Seven-year survival was poorer in the elderly with respect to overall survival, (49 +/- 6% vs. 72 +/- 3%, p = 0.0001), freedom from complications-related death (57 +/- 7% vs. 79 +/- 3%, p = 0.001), from death due to myocardial failure (66 +/- 6% vs. 86 +/- 3%, p < 0.0001) and from overt myocardial failure (44 +/- 7% vs. 74 +/- 3%, p = 0.0001). Multivariate analysis showed better survival with younger age, mitral valve repair, better preoperative NYHA class and better left ventricular function. However, 7-year freedom from complications-related death was excellent and similar in both elderly (90 +/- 7%) and younger (93 +/- 3%, NS) patients who underwent surgery early while in NYHA class I or II with left ventricular ejection fraction > 40%. CONCLUSIONS: Late surgery contributes far more than age itself to poor outcome from mitral valve surgery in the elderly. If surgery is performed early and repair preferred to replacement whenever feasible, medium-term results are excellent in both young and old.

Age Factors↗
PubMed1997

Echocardiography in mitral valve repair for mitral regurgitation: the surgeon's needs.

Mitral valve repair has become the operation of choice for mitral regurgitation. It is often technically more demanding than valve replacement. The role of echocardiography has now extended beyond the identification of severe mitral regurgitation that would benefit from surgical correction. It helps the surgeon to assess valve reparability preoperatively, to assess the need for valve surgery in equivocal cases of ischemic mitral regurgitation, to plan the operation, and to assess valve function after repair. This article aims to discuss the role of echocardiography in providing the information needed by the surgeon for successful mitral valve repair. The echocardiographer must understand the surgeon's needs, while surgeons should understand both the benefits and limitations of echocardiography.

Diagnosis, Differential↗
PubMed1996

Importance of subvalvular preservation and early operation in mitral valve surgery.

BACKGROUND: Mitral valve replacement (MVR) has a high mortality and morbidity. It has been suggested that preservation of the subvalvular apparatus and more optimal timing of surgery might improve outcome. METHODS AND RESULTS: We performed a retrospective study of 612 consecutive patients who underwent mitral valve repair or replacement: 226 patients had repair, 68 had replacement with subvalvular preservation (MVR/SVP), and 318 had replacement without subvalvular preservation (MVR/NoSVP). Baseline characteristics were most unfavorable in the repair group with respect to age (P = .002) and in the repair and MVR/SVP groups with respect to NYHA functional class and left ventricular function (P = .044). Thirty-day mortality was lower in the repair (1.8%, P = .046) and MVR/SVP (1.5%. P = NS) groups than the MVR/NoSVP group (5.0%). Overall survival at 7 years was better in the repair (71.2 +/- 5.6%. P = .022) and MVR/SVP (66.2 +/- 12.4%, P = .017) groups than the MVR/NoSVP group (63.5 +/- 3.4%). Myocardial failure caused 66 of 107 complication-related deaths. Multivariate analysis confirmed independent beneficial effects of repair on 30-day mortality (odds ratio, 0.27, P < .05) and of repair and MVR/SVP on overall mortality (hazard ratios, 0.43, P < .001 and 0.40, P < .05, respectively) and complication-related death hazard ratios, 0.38, P < .001 and 0.35, P < .05, respectively). Preoperative NYHA class III or IV symptoms and left ventricular impairment were independent risk factors for death and myocardial failure. CONCLUSIONS: Mitral valve repair is superior to replacement. If repair is not feasible, the subvalvular apparatus should be preserved. Early surgery before the development of severe symptoms and demonstrable left ventricular impairment is also needed to optimize outcome.

Aged↗
PubMed1996

Changing from intensive anticoagulation to treatment with aspirin alone for coronary stents: the experience of one centre in the United Kingdom.

OBJECTIVE: To investigate whether an elective change in the anticoagulation protocol for patients with coronary stents affected clinical outcomes and length of hospital stay. DESIGN: Retrospective observational study of a consecutive series of patients treated with coronary stents over an 18 month period from April 1994 to October 1995. BACKGROUND: Intensive anticoagulation regimens are used in many UK centres to reduce the risk of coronary stent thrombosis. Recent data have called into question the necessity for full anticoagulation and favourable results have been reported with antiplatelet agents alone. The results from a tertiary referral centre were investigated during a period where an elective change in policy was made: an initial 70 patients were treated intensively with intravenous heparin and with warfarin and aspirin; subsequently 94 were treated with aspirin and deployment of a high pressure balloon only. METHODS: Review of case notes, angiograms, and a database of intervention procedures and telephone interview. Classic epidemiological techniques, as well as linear regression and logistic regression, were used to model the outcomes of major procedural complications and length of hospital stay. PATIENTS: 164 patients treated with 196 coronary stents. RESULTS: There were 22 (13.4%) major complications (coronary bypass grafting 11, subacute thrombosis 6, tamponade 2, myocardial infarction 1, death 2). With logistic regression, the risk of major complication was shown not to be affected by anticoagulation (relative risk (RR) 1.03; P = 0.97). Significant determinants of risk included acute vessel closure as an indication for stenting (RR = 80.6; P < 0.001) and sex (male: female RR = 0.19; P = 0.02). The median length of stay (LOS) was 5 days (1-45). Use of a linear regression model showed that anticoagulation added 4.5 days and a major complication added a further 4.5 days to a baseline length of stay of 3.2 days (R2 = 0.32; P < 0.001). CONCLUSION: This is a report of coronary stenting as part of usual clinical practice in one British tertiary referral centre. In this experience, treatment with aspirin alone is probably as safe as intensive anticoagulation, and has the benefit of reducing length of stay by more than 50% to 3.2 days in an uncomplicated case.

Anticoagulants↗
PubMed1995

Noninvasive assessment of left internal mammary artery graft patency using transthoracic echocardiography.

BACKGROUND: Cardiac catheterization is the only practical method of assessing internal mammary artery graft patency. A noninvasive method would be useful in patients with recurrence of anginal symptoms after coronary artery bypass graft surgery. We hypothesized that transthoracic echocardiography could provide information on blood velocity and anatomy and therefore has the potential to allow measurement of blood flow. METHODS AND RESULTS: High-frequency (5 MHz) transthoracic echocardiography was performed on 41 consecutive patients (mean age, 67 +/- 6 years) who had had left internal mammary artery grafts to the left anterior descending coronary artery (LAD) and were undergoing coronary angiography because of recurrence of anginal symptoms. The results were compared with those from 19 patients (mean age, 58 +/- 11 years) in whom an ungrafted left internal mammary artery was assessed and with those from 15 patients (mean age, 61 +/- 12 years) who had angiographically normal coronary arteries in whom the LAD was studied. Doppler velocity profiles of the left internal mammary graft were obtained in 35 of the 41 study patients (81%). In all cases, a biphasic pattern of blood flow was recorded that corresponded to systole and diastole. Two different flow patterns were observed. In 25 patients with a normal graft or moderate (< 70%) stenosis (group A), blood flow velocity was maximal during diastole. This pattern was also seen in the LAD control group. In 10 patients with severe (> 70%) graft stenosis (group B), blood velocity was maximal during systole, and low velocities were recorded during diastole. This pattern was also seen in the ungrafted internal mammary artery control group. The diastolic fraction of the velocity time integrals for group A was 0.77 +/- 0.07 and for group B was 0.27 +/- 0.01 (P < .05). A diastolic velocity time integral fraction < 0.5 predicted severe stenosis with a sensitivity and specificity of 100%. The ratio of systolic-to-diastolic peak velocities for group A was 0.54 +/- 0.26 and for group B was 3.45 +/- 0.74 (P < .05). A systolic-to-diastolic peak velocity ratio > 1 predicted severe stenosis with a sensitivity of 100% and specificity of 85%. Mean graft blood flow was 63 +/- 21 mL/min. There was no significant difference in mean blood flow between any of the patient groups studied. CONCLUSIONS: High-frequency transthoracic echocardiography allows identification of the left internal mammary grafts and measurement of blood flow. Compared with patent grafts or those with moderate lesions, severe stenoses demonstrated different Doppler velocity patterns. Use of this technique may allow noninvasive detection of significant stenoses of the left internal mammary artery graft.

Aged↗
PubMed1995

Identification of right atrial thrombi using transoesophageal echocardiography.

The in vivo diagnosis of right atrial thrombus is difficult by transthoracic echocardiography and it is likely that small thrombi are underdiagnosed using this approach. Transoesophageal echocardiography provides an unobstructed view of cardiac structures and the great vessels. In this report we describe the findings in five patients with right atrial thrombi that illustrate the potential usefulness of transoesophageal echocardiography for both the initial diagnosis and the subsequent management of these patients.

Adult↗
PubMed1995

Mortality and morbidity after mitral valve repair: the importance of left ventricular dysfunction.

A retrospective study of 219 consecutive patients who underwent mitral valve repair for mitral regurgitation or mixed mitral valve disease with at least moderate regurgitation was undertaken. The etiology was degenerative in 151 (68.9%) patients, endocarditis in 24 (10.9%), rheumatic in 22 (10.0%), ischemic in 13 (5.9%), congenital in five (2.3%) and cardiomyopathy in two (0.9%). The average age was 64.8 +/- 10.9 years, the average follow up 30.2 +/- 24.1 months. Pre-operatively, 74% were in NYHA functional class III or IV. Left ventricular function was assessed by angiography and echocardiography, and moderate or severe impairment (ejection fraction < or = 40%) was assumed to represent significant left ventricular dysfunction. There were six (2.7%) hospital deaths, four of which were due to left ventricular dysfunction. The seven-year mortality and seven-year combined mortality and morbidity were 14.4% and 37.1% respectively for complications related to left ventricular dysfunction, and 2.5% and 24.2% respectively for unrelated complications. Subgroup analysis showed that five-year mortality and five-year combined mortality and morbidity due to left ventricular dysfunction were significantly worse in patients who had pre-operative left ventricular dysfunction than those who did not: 28.5% vs. 6.1% (p < 0.001) and 52.4% vs. 17.8% (p < 0.001). There was nevertheless a significant incidence of postoperative left ventricular dysfunction in patients with satisfactory preoperative left ventricular function. In this group, five-year mortality and five-year combined mortality and morbidity due to left ventricular dysfunction were higher in patients who were in NYHA class III or IV preoperatively than in those who were not: 11.2% vs. 0% (NS) and 25.9% vs. 0% (p < 0.01) respectively, particularly if they also had early (3-10 days) post-operative left ventricular dysfunction: 20.4% (p < 0.001) and 41.7% (p < 0.001) respectively. Despite preservation of the mitral apparatus, left ventricular dysfunction remains a major cause of mortality and morbidity following mitral valve repair for mitral regurgitation.

Adolescent↗
PubMed1994

Early complications after dual chamber versus single chamber pacemaker implantation.

This study was performed to compare the frequency of early complications after single chamber versus dual chamber permanent pacemaker implantation. Early complication was defined as one occurring in the 6-week period following implantation. We prospectively analyzed consecutive pacemaker implantation from January 1987 to June 1993 at our regional center. All complications were also analyzed for the relationship to operator experience, the venous access route, and the presence of temporary pacing wire at the time of implantation of the permanent pacing system. A total of 2019 new pacemaker units were implanted during this period. 1733 patients (85.8%) received a VVI pacemaker and 286 (14.2%) a DDD unit. Wound infection occurred in 11 (0.6%) VVI patients and 6 (2.1%) DDD patients. Lead displacement occurred in 18 (1%) VVI patients and 15 (5.2%) DDD patients (11 [3.8%] atrial and 4 [1.4%] ventricular). There were 10 (0.6%) pneumothoraces, 9 (0.5%) hematomas requiring drainage, 1 (0.06%) chylocele, and 2 (0.1%) deaths in the VVI group. There were 2 (0.7%) pneumothoraces, 2 (0.7%) hematomas, and no deaths in the DDD group. There was no significant increase in complications for experienced infrequent implanters (< 12 systems per year). In both groups the subclavian approach was associated with a risk of pneumothorax when compared to the cephalic approach. The rate of wound infection was higher in patients who had a temporary pacing wire in place. The use of prophylactic antibiotics does not appear to affect the incidence of wound infection.(ABSTRACT TRUNCATED AT 250 WORDS)

Anti-Bacterial Agents↗
PubMed1994

Profiles of coronary blood flow velocity in patients with aortic stenosis and the effect of valve replacement: a transthoracic echocardiographic study.

OBJECTIVE: To report the first non-invasive assessment by transthoracic Doppler echocardiography of coronary blood flow in patients with aortic stenosis and of the effects of valve replacement. DESIGN: High frequency transthoracic Doppler echocardiography was used to examine resting phasic flow in the left anterior descending coronary artery before and after replacement of the aortic valve in awake, unsedated patients with pure aortic stenosis and normal coronary arteries. SETTING: A tertiary referral cardiothoracic centre. METHODS: Eleven patients with pure aortic stenosis and normal coronary arteries (six men, five women, mean (range) age 69 (50-82) years), were studied the day before and 1 week after replacement of the aortic valve. These patients were selected from a cohort of 15 due to ease of imaging of the left anterior descending coronary artery. Seven had a history of angina. Haemodynamics, peak transvalvar aortic gradient, left ventricular mass index, ventricular dimensions, and profiles of coronary flow velocity were measured. Profiles of coronary flow velocity were also measured in a control population of 10 normal subjects (five men, five women, mean (range) age 58 (34-66) years). RESULTS: The control population showed forward flow throughout systole, but reversed early systolic flow (mean velocity 20.6 (3.6) cm/s) was seen in six patients with aortic stenosis. Only three of these patients had a clinical history of angina. Peak and mean systolic and diastolic forward flow velocities were not significantly different in the control group and in patients with aortic stenosis. The time from the start of systole to the onset of forward systolic flow was significantly longer in patients with aortic stenosis than in the control population (185 (8.5) v 85 (10) ms, p < 0.01). The time from the onset of diastolic flow to peak diastolic velocity was also significantly longer in the aortic stenosis group (146 (16) v 74 (13) ms, p < 0.01). These abnormalities in profiles of coronary flow were reversed by replacement of the aortic valve. There was no correlation between changes in flow profiles in patients with aortic stenosis and preoperative clinical history, transvalvar gradient, left ventricular mass index, or ventricular dimensions. CONCLUSIONS: Coronary flow profiles in patients with aortic stenosis were characterised by reversed early systolic flow and delayed forward systolic flow and attainment of peak diastolic velocity. Reversal of these abnormalities by replacement of the aortic valve may reflect altered left ventricular and aortic haemodynamics and contribute to the relief of angina when left ventricular hypertrophy persists. Further studies may correlate abnormalities of coronary flow with preoperative clinical and haemodynamic state.

Aged↗
PubMed1994

Identification of coronary artery stenoses and poststenotic blood flow patterns using a miniature high-frequency epicardial transducer.

BACKGROUND: Intraoperative epicardial coronary Doppler ultrasound has the potential to provide anatomic and functional information. This technique has been hindered by the large size of standard transducers, but a miniature transducer is available that may fulfill the potential of coronary ultrasound. METHODS AND RESULTS: Twenty consecutive patients who were undergoing coronary artery bypass grafting were studied and compared with 9 control patients with normal coronary arteries who were undergoing routine mitral valve surgery. A miniature 6.5-MHz transducer was used to image coronary arteries and measure coronary blood flow velocities. Seventeen proximal left anterior descending and 3 right coronary artery stenoses were studied. As defined by coronary angiography (1 to 34 days before surgery), there were 13 severe stenoses (> 70%), 4 moderate stenoses (40% to 70%), 2 minor stenoses (< 40%), and 1 subtotal occlusion. Stenoses were readily identified by ultrasound. Color flow mapping demonstrated laminar flow in normal arteries and nonlaminar flow across moderate and severe stenoses. In the control patients with unobstructed arteries, peak and mean diastolic velocities were 35 +/- 2.1 and 26 +/- 1.9 cm/s with peak and mean systolic velocities of 16 +/- 1.4 and 11 +/- 0.8 cm/s, respectively. Prestenotic flow velocities were not significantly different from normal control values, but a wide range of poststenotic flow disturbances were detected. Analysis of the 20 study patients did not reveal significant differences in poststenotic compared with prestenotic flow. A subgroup analysis of 12 patients with severe left anterior descending coronary artery stenoses was performed, and reversed poststenotic systolic flow was seen in 9. Prestenotic peak and mean systolic velocities were 16.5 +/- 1.7 and 11.9 +/- 1.1 cm/s, respectively, and were significantly altered downstream of the stenoses at -22.7 +/- 17.2 and -15.9 +/- 10.9 cm/s (P < .05 and P < .01, respectively). Reversed systolic flow was seen only distal to severe left anterior descending coronary artery stenoses and did not correlate with retrograde collateral filling as determined by preoperative coronary angiography. Moderate stenoses appeared to increase both systolic and diastolic components of poststenotic flow. CONCLUSIONS: Epicardial Doppler ultrasound with a miniature transducer identifies coronary stenoses and associated blood flow disturbances. Compared with moderate lesions, severe stenoses demonstrated different poststenotic flow patterns. Intraoperative use of this technique may determine the hemodynamic significance of coronary stenoses.

Adult↗
PubMed1994

Magnetic resonance imaging planes for the 3-dimensional characterisation of human coronary arteries.

We report a magnetic resonance imaging study which developed a consistent hierarchy of imaging planes for examination of the origins, courses and principal branches of the main coronary arteries of prepared human cadaveric hearts. The reference longitudinal axis was chosen between the aortic valve and the apex of the left ventricle. A series of transverse planes then successfully visualised the ostia of the left and right coronary arteries; the left main coronary, its bifurcation, and the left anterior descending artery for a distance 24 mm distal to its origin were clearly distinct in successively posterior sections as was the emergence and course of the right coronary artery. Further sections were derived from an axis that joined the posterior aspects of the left and right coronary artery ostia seen in cross-section, which demonstrated the origins of these arteries. They also traced the circumflex artery 30 mm beyond its point of emergence and demonstrated the course of the right coronary artery between the right ventricle and right atrium. The anatomical identifications were confirmed in selective 3-dimensional reconstructions of the cardiac anatomy around the aortic root and pulmonary artery origin. The orthogonal anatomical arrangements of the left and right coronary artery arterial trees thus permit a consistent set of imaging planes useful for the visualisation of all the major branches in a static heart in vitro. This may offer an approach useful for clinical imaging of human coronary vessels in vivo in the moving heart.

Aged↗
PubMed1992

Transthoracic high-frequency two-dimensional echocardiography, Doppler and color flow mapping to determine anatomy and blood flow patterns in the distal left anterior descending coronary artery.

Combined high-frequency transthoracic ultrasound, pulsed Doppler and color flow mapping were used to image and assess blood flow velocity in the distal left anterior descending artery (LAD) in 56 consecutive patients. All patients subsequently underwent coronary angiography. The LAD was imaged in 19 patients (34%), and the diameter was measured in 12 with high-quality images (mean diameter 1.8 mm +/- 0.08). In 1 patient, the penetrating branches of the LAD were imaged. The distal LAD appeared normal by ultrasound in 18 patients, and a significant stenosis was detected in 1; angiography confirmed the ultrasound findings. There were no false negative results. Characteristic biphasic flow with higher velocities in diastole were noted in all 19 patients. Color flow mapping demonstrated normal laminar flow, except in the patient with a distal stenosis. Pulsed Doppler confirmed an increased velocity distal to the stenosis in this patient. This study is the first transthoracic evaluation of the hemodynamic effects of a coronary artery stenosis, and the first in vivo description of blood flow disturbance at a distal coronary stenosis in humans. The clinical use of this technique is limited, because only the distal portion of the LAD is visualized. However, it may provide a noninvasive means of assessing distal LAD diameter and blood flow, and changes in these parameters under a variety of physiologic, pharmacologic and interventional stimuli.

Adolescent↗
PubMed1992

Sudden cardiac death in athletes.

Sudden death in athletes is a rare but tragic occurrence. Congenital cardiovascular abnormalities, usually asymptomatic and often undiagnosed during life, are the main causes in young athletes. Hypertrophic cardiomyopathy and congenital coronary anomalies are the most commonly occurring disorders. Idiopathic concentric left ventricular hypertrophy (non-physiological), arrhythmogenic right ventricular dysplasia and Marfan's syndrome with aortic rupture have also been implicated. Rarer causes include mitral valve prolapse and myocarditis. Coronary atherosclerosis is the major cause in older, and occasionally in younger athletes. Those involved in the medical care of athletes should be aware of the potential causes of sudden death in these groups. Symptomatic athletes should be fully investigated. Screening programmes are probably not justified on a cost effective basis.

Adult↗