Patrick T. O'Gara

Surgical treatment of moderate ischemic mitral regurgitation.

BACKGROUNDnIschemic mitral regurgitation is associated with increased mortality and morbidity. For surgical patients with moderate regurgitation, the benefits of adding mitral-valve repair to coronary-artery bypass grafting (CABG) are uncertain.nnnMETHODSnWe randomly assigned 301 patients with moderate ischemic mitral regurgitation to CABG alone or CABG plus mitral-valve repair (combined procedure). The primary end point was the left ventricular end-systolic volume index (LVESVI), a measure of left ventricular remodeling, at 1 year. This end point was assessed with the use of a Wilcoxon rank-sum test in which deaths were categorized as the lowest LVESVI rank.nnnRESULTSnAt 1 year, the mean LVESVI among surviving patients was 46.1±22.4 ml per square meter of body-surface area in the CABG-alone group and 49.6±31.5 ml per square meter in the combined-procedure group (mean change from baseline, -9.4 and -9.3 ml per square meter, respectively). The rate of death was 6.7% in the combined-procedure group and 7.3% in the CABG-alone group (hazard ratio with mitral-valve repair, 0.90; 95% confidence interval, 0.38 to 2.12; P=0.81). The rank-based assessment of LVESVI at 1 year (incorporating deaths) showed no significant between-group difference (z score, 0.50; P=0.61). The addition of mitral-valve repair was associated with a longer bypass time (P<0.001), a longer hospital stay after surgery (P=0.002), and more neurologic events (P=0.03). Moderate or severe mitral regurgitation was less common in the combined-procedure group than in the CABG-alone group (11.2% vs. 31.0%, P<0.001). There were no significant between-group differences in major adverse cardiac or cerebrovascular events, deaths, readmissions, functional status, or quality of life at 1 year.nnnCONCLUSIONSnIn patients with moderate ischemic mitral regurgitation, the addition of mitral-valve repair to CABG did not result in a higher degree of left ventricular reverse remodeling. Mitral-valve repair was associated with a reduced prevalence of moderate or severe mitral regurgitation but an increased number of untoward events. Thus, at 1 year, this trial did not show a clinically meaningful advantage of adding mitral-valve repair to CABG. Longer-term follow-up may determine whether the lower prevalence of mitral regurgitation translates into a net clinical benefit. (Funded by the National Institutes of Health and the Canadian Institutes of Health Research; ClinicalTrials.gov number, NCT00806988.).

Acute Aortic Dissection and Its Variants Toward a Common Diagnostic and Therapeutic Approach

Acute dissection of the aorta is an uncommon yet potentially catastrophic clinical event that mandates prompt recognition and expeditious treatment. Diagnosis begins with a high clinical index of suspicion in a patient presenting with chest pain and one or more predisposing risk factors, most notably, hypertension or an inherited disorder of connective tissue. Verification can be rapidly achieved with a high degree of accuracy using one of several noninvasive imaging techniques and, when necessary, contrast angiography. Involvement of the ascending aorta (type A) requires surgical intervention, whereas clinically stable dissection limited to the descending thoracic aorta (type B) can in general be treated medically. Negative inotropic andantihypertensive medical therapy is provided to all patients. Hospital and long-term survival has improved substantially over the past 40 years, yet there remains ample room for continued progress. For centers with an active interest in the evaluation and management of acute dissection, hospital mortality rates have been lowered to 15% to 25%.1 2 3 Five-year actuarial survival rates range between 50% and 70%,2 4 5 with a 7% to 20% incidence of late reoperation, usually for aneurysmal enlargement or redissection.2 6 7 nnThere has long been some debate over the pathogenesis of aortic dissection. In the majority of cases, the initiating event is a tear in the intima of the aorta through which blood surges into the middle to outer third of the media.8 9 10 Intimal disease, such as that associated with atherosclerosis, is not a prerequisite, although underlying medial disease due to both elastic fiber and smooth muscle cell degeneration is the rule.11 12 13 Intimal tears are most commonly located a few centimeters above the aortic valve, along the right anterolateral aspect of the aorta, where hydrodynamic and torsional forces are greatest.9 The second most …

Predicting recurrent mitral regurgitation after mitral valve repair for severe ischemic mitral regurgitation

OBJECTIVESnThe Cardiothoracic Surgical Trials Network recently reported no difference in the primary end point of left ventricular end-systolic volume index at 1 year postsurgery in patients randomized to repair (n = 126) or replacement (n = 125) for severe ischemic mitral regurgitation. However, patients undergoing repair experienced significantly more recurrent mitral regurgitation than patients undergoing replacement (32.6% vs 2.3%). We examined whether baseline echocardiographic and clinical characteristics could identify those who will develop moderate/severe recurrent mitral regurgitation or die.nnnMETHODSnOur analysis includes 116 patients who were randomized to and received mitral valve repair. Logistic regression was used to estimate a model-based probability of recurrence or death from baseline factors. Receiver operating characteristic curves were constructed from these estimated probabilities to determine classification cut-points maximizing accuracy of prediction based on sensitivity and specificity.nnnRESULTSnOf the 116 patients, 6 received a replacement before leaving the operating room; all other patients had mild or less mitral regurgitation on intraoperative echocardiogram after repair. During the 2-year follow-up period, 76 patients developed moderate/severe mitral regurgitation or died (53 mitral regurgitation recurrences, 13 mitral regurgitation recurrences and death, and 10 deaths). The mechanism for recurrent mitral regurgitation was largely mitral valve leaflet tethering. Our model (including age, body mass index, sex, race, effective regurgitant orifice area, basal aneurysm/dyskinesis, New York Heart Association class, history of coronary artery bypass grafting, percutaneous coronary intervention, or ventricular arrhythmias) yielded an area under the receiver operating characteristic curve of 0.82.nnnCONCLUSIONSnThe model demonstrated good discrimination in identifying patients who will survive 2 years without recurrent mitral regurgitation after mitral valve repair. Although our results require validation, they offer a clinically relevant risk score for selection of surgical candidates for this procedure.

Futility, benefit, and transcatheter aortic valve replacement.

Transcatheter aortic valve replacement (TAVR) is a transformative innovation that provides treatment for high or prohibitive surgical risk patients with symptomatic severe aortic stenosis who either were previously not referred for or were denied operative intervention. Trials have demonstrated improvements in survival and symptoms after TAVR versus medical therapy;xa0however, there remains a sizable group of patients who die or lack improvement in quality of life soon after TAVR. This raises important questions about the need to identify and acknowledge the possibility of futility in some patients considered for TAVR. In this very elderly population, a number of factors in addition to traditional risk stratification need to be considered including multimorbidity, disability, frailty, and cognition in order to assess the anticipated benefit of TAVR. Consideration by a multidisciplinary heart valve team with broad areas of expertise is critical for assessing likely benefit from TAVR. Moreover, these complicated decisions should take place with clear communication around desired health outcomes on behalf of the patient and provider. The decision that treatment with TAVR is futile should include alternative plans to optimize the patients health state or, in some cases, discussions related to end-of-life care. We review issues to be considered when making and communicating these difficult decisions.

Aortic valve and ascending aorta guidelines for management and quality measures: executive summary.

The Society of Thoracic Surgeons Clinical Practice Guidelines are intended to assist physicians and other health care providers in clinical decision making by describing a range of generally acceptable approaches for the diagnosis, management, or prevention of specific diseases or conditions. These guidelines should not be considered inclusive of all proper methods of care or exclusive of other methods of care reasonably directed at obtaining the same results. Moreover, these guidelines are subject to change over time, without notice. The ultimate judgment regarding the care of a particular patient must be made by the physician in light of the individual circumstances presented by the patient.

Aortic expansion after acute type B aortic dissection.

BACKGROUNDnA considerable number of patients with acute type B aortic dissection (ABAD) treated with medical management alone will exhibit aortic enlargement during follow-up, which could lead to aortic aneurysm and rupture. The purpose of this study was to investigate predictors of aortic expansion among ABAD patients enrolled in the International Registry of Acute Aortic Dissection.nnnMETHODSnWe analyzed 191 ABAD patients treated with medical therapy alone enrolled in the registry between 1996 and 2010, with available descending aortic diameter measurements at admission and during follow-up. The annual aortic expansion rate was calculated for all patients, and multivariate regression analysis was used to investigate factors affecting the expansion rate.nnnRESULTSnAortic expansion was observed in 59% of ABAD patients; mean expansion rate was 1.7±7 mm/y. In multivariate analysis, white race (regression coefficient [RC], 4.6; 95% confidence interval [CI], 1.4 to 7.7) and an initial aortic diameter less than 4.0 cm (RC, 6.3; 95% CI, 4.0 to 8.6) were associated with increased aortic expansion. Female sex (RC, -3.8; 95% CI, -6.1 to -1.4), intramural hematoma (RC, -3.8; 95% CI, -6.5 to -1.1), and use of calcium-channel blockers (RC, -3.8; 95% CI, -6.2 to -1.3) were associated with decreased aortic expansion.nnnCONCLUSIONSnWhite race and a small initial aortic diameter were associated with increased aortic expansion during follow-up, and decreased aortic expansion was observed among women, patients with intramural hematoma, and those on calcium-channel blockers. These data raise the possibility that the use of calcium-channel blockers after ABAD may reduce the rate of aortic expansion, and therefore further investigation is warranted.

Diagnosis and treatment of tricuspid valve disease: current and future perspectives

The assessment and management of tricuspid valve disease have evolved substantially during the past several years. Whereas tricuspid stenosis is uncommon, tricuspid regurgitation is frequently encountered and is most often secondary in nature and caused by annular dilatation and leaflet tethering from adverse right ventricular remodelling in response to any of several disease processes. Non-invasive assessment of tricuspid regurgitation must define its cause and severity; advanced three-dimensional echocardiography, MRI, and CT are gaining in clinical application. The indications for tricuspid valve surgery to treat tricuspid regurgitation are related to the cause of the disorder, the context in which it is encountered, its severity, and its effects on right ventricular function. Most operations for tricuspid regurgitation are done at the time of left-sided heart valve surgery. The threshold for restrictive ring annuloplasty repair of secondary tricuspid regurgitation at the time of left-sided valve surgery has decreased over time with recognition of the risk of progressive tricuspid regurgitation and right heart failure in patients with moderate or lesser degrees of tricuspid regurgitation and tricuspid annular dilatation, as well as with appreciation of the high risks of reoperative surgery for severe tricuspid regurgitation late after left-sided valve surgery. However, many patients with unoperated severe tricuspid regurgitation are also deemed at very high or prohibitive surgical risk. Novel transcatheter therapies have begun to emerge for the treatment of tricuspid regurgitation in such patients. Experience with such therapies is preliminary and further studies are needed to determine their role in the management of this disorder.

Do gender-based differences in presentation and management influence predictors of hospitalization costs and length of stay after an acute myocardial infarction?

Previous studies have reported conflicting results on gender differences in the management of acute myocardial infarction (AMI) and have not evaluated hospital length of stay or costs. To determine gender-based differences in presentation, management, length of stay, costs, and prognosis after AMI, we studied 561 patients with AMI. Women were older, had systemic hypertension, diabetes mellitus, and a non-Q-wave AMI more frequently, whereas more men smoked cigarettes. Predictors of coronary angiography were: male gender (RR 1.9; 95% CI 1.2 to 3.1), chest pain at presentation (RR 1.8; 95% CI 1.0 to 3.3), recurrent angina (RR 4.1; 95% CI 2.5 to 6.8), admission via the emergency room (RR 0.2; 95% CI 0.1 to 0.3), and younger age. Gender did not predict mortality. Among presenting features, the predictors of length of stay were diabetes, prior coronary bypass and prior coronary angioplasty in men, and age alone in women. Pulmonary edema and need for coronary bypass during the hospital course were predictors of length of stay in men only. Among presenting features, predictors of cost were diabetes in men and congestive heart failure in women. Predictors of cost during hospitalization for men were pulmonary edema, coronary angiography, intraaortic balloon pump use, and coronary bypass; for women, they were peak levels of creatine kinase and coronary bypass. Thus, predictors of length of stay and hospitalization costs differ based on gender. Efforts at cost containment may need to be gender-specific.

Does Circadian and Seasonal Variation in Occurrence of Acute Aortic Dissection Influence in‐Hospital Outcomes?

The risk of acute aortic dissection (AAD) exhibits chronobiological variations with peak onset in the morning and in winter. However, it is not known whether the time of day or season of the year of the AAD affects clinical outcomes. We studied 1,032 patients enrolled in the International Registry of Acute Aortic Dissection from January 1997 to December 2001. For circadian and seasonal analysis, the time and date of symptom onset were available for 741 and 1,007 patients, respectively, and were grouped into four 6 h periods (morning, afternoon, evening, and night) and four seasons (winter, spring, summer, and autumn). The χ2 test for goodness of fit was used to evaluate non‐uniformity of the time of day and time of year for critical in‐hospital clinical events, including death. While highest incidence of AAD occurred in the morning and winter, clinical events (including mortality) were similar during the four different periods of the 24 h (χ2=1.9, p=0.60) and seasonal (χ2=1.2, p=0.75) periods.

Association of Coronary Stenosis and Plaque Morphology With Fractional Flow Reserve and Outcomes

IMPORTANCEnObstructive coronary lesions with reduced luminal dimensions may result in abnormal regional myocardial blood flow as assessed by stress-induced myocardial perfusion imaging or a significant fall in distal perfusion pressure with hyperemia-induced vasodilatation (fractional flow reserve [FFR] ≤0.80). An abnormal FFR has been demonstrated to identify high-risk lesions benefitting from percutaneous coronary intervention while safely allowing revascularization to be deferred in low-risk lesions, resulting in a decrease in the number of revascularization procedures as well as substantially reduced death and myocardial infarction. While FFR identifies hemodynamically significant lesions likely to produce ischemia-related symptoms, it remains less clear as to why it might predict the risk of acute coronary syndromes, which are usually due to plaque rupture and coronary thrombosis.nnnOBSERVATIONSnAlthough the atherosclerotic plaques with large necrotic cores (independent of the degree of luminal stenosis) are known to be associated with vulnerability to rupture and acute coronary syndromes, emerging evidence also suggests that they may induce greater rates of ischemia and reduced FFR compared with non-lipid-rich plaques also independent of the degree of luminal narrowing. It is proposed that the presence of large necrotic cores within the neointima may be associated with the inability of the vessel to dilate and may predispose to ischemia and abnormal FFR.nnnCONCLUSIONS AND RELEVANCEnHaving a normal FFR requires unimpaired vasoregulatory ability and significant luminal stenosis. Therefore, FFR should identify lesions that are unlikely to possess large necrotic core, rendering them safe for treatment with medical therapy alone. Further studies are warranted to determine whether revascularization decisions in patients with stable coronary artery disease could be improved by assessment of both plaque composition and ischemia.