Sessão do Departamento de Imagem Cardiovascular / SBC-Ba

Mitral regurgitation: Early hazard, later gains following TAVI - by heart.org

Vancouver, BC and Quebec City, QU - Moderate to severe mitral regurgitation (MR) is relatively common in patients undergoing transcatheter aortic-valve implantation (TAVI) and is associated with a doubling in risk of 30-day death, a new series suggests [1]. Beyond this initial period, however, survival among MR patients is just as good as among patients with no MR, and MR itself is likely to improve over time, authors of a new analysis say.

 

The paper, by Dr Stefan Toggweiler (St Paul's Hospital, Vancouver, BC) and colleagues, is published online April 4, 2012 in the Journal of the American College of Cardiology.

To heartwire, Toggweiler explained that the percentage of patients undergoing TAVI who also have moderate to severe MR has varied across reports, ranging from 25% to 45%. Severe MR was actually an exclusion criterion in the pivotal PARTNER trials, but many patients made it into the trial with a diagnosis of "moderate" MR that was only upgraded after the core lab reviewed the echocardiograms, meaning that even in PARTNER there are subset data on patients with significant MR.

Toggweiler et al tracked outcomes of 478 patients treated over a five-year period at two centers in Canada. (Devices used over this period were the Edwards-Cribier valve [n=56], Edwards Sapien [n=270], and Sapien XT [n=115]). Although the bulk of patients had mild or no MR, 89 had moderate MR, and 43 had severe MR.

At 30 days, mortality among patients with moderate or severe MR was twice as high as among those with mild or less MR (hazard ratio [HR] 2.10, p=0.02); after 30 days and up to two years, however, mortality rates were no different between these groups (HR 0.82, p=0.42).

Of note, among survivors, MR had improved in 55% of subjects, remained the same in another 16%, and had worsened in just 1%. Among those with moderate or severe MR at baseline, 61% of patients experienced some improvement post-TAVI.

"Short-term mortality is a bit higher after TAVI, and in general, these patients are a bit older and have more comorbidities, so certainly immediately postoperative, the risk is a bit higher and they require careful monitoring," Toggweiler summarized. "But again, if they are not treated, they probably don't do well because the combination of MR and aortic stenosis is not well tolerated at all."

To heartwire, he noted that a similar pattern of early hazard post-TAVI, followed by improved outcomes after the 30-day mark, was seen in PARTNER, although the numbers were very low.

Given these findings, he continued, "the advice would be that these patients [who also have moderate to severe MR at the time of their TAVI procedures] need careful monitoring, and we have identified some factors that actually are associated with good outcomes." These include patients with higher mean transaortic gradient at baseline, no atrial fibrillation, no pulmonary hypertension, and functional as opposed to structural MR. "So these [patients] may be candidates for isolated TAVI," Toggweiler said.

Pointing to the fact that MR actually improved in 61% of subjects, Toggweiler noted that there are likely different mechanisms by which patients, if they survive the early postop period, actually do better in the long term.

"What is most likely [happening] is, because the afterload is reduced immediately—because there is no stenosis—there is less pressure gradient between the left ventricle and left atrium, and that leads to reduced MR in the short term. And then some patients have positive remodeling post-TAVI, ejection fraction improves, and that leads to improvement in the long term."

Curiosidade da semana (Agora ficou fácil...) - by Fábio Soares

O que vemos nessa imagem?

Será que ajudaria dizer que o paciente apresenta Hipertensão Arterial Pulmonar grave? E com o eixo curto, já observaram a pegadinha?

Hipertensão Arterial Pulmonar Grave acompanhada de grave hipertrofia do VD e de sua trabécula septomarginalis. À primeira vista, temos a impressão de que o SIV está normal e há um grande tendão móvel no VE, porém o que ocorre é o movimento paradoxal do SIV devido a pressão do VD bastante elevada.

"The septomarginal trabecula (also known as moderator band) is a muscular band of heart tissue found in the right ventricle. It is well-marked in sheep and some other animals, and frequently extends from the base of the anterior papillary muscle to the ventricular septum.

This septomarginal trabecula is important because it carries part of the right bundle branch of the AV bundle of the conduction system of the heart to the anterior papillary muscle. This shortcut across the chamber of the ventricle seems to facilitate conduction time, allowing coordinated contraction of the anterior papillary muscle."

Resposta do caso clínico - by Fábio Soares

Nota-se grande trombo ocupando o ápice do ventrículo esquerdo (área acinética), bastante móvel e com características recentes (várias fases). Este paciente permaneceu internado em ajuste de medidas para disfubnção ventricular, uso de dupla agregação plaquetária e anticoagulação plena com Heparina de baixo peso molecular.

Após 1 semana,repito o ecocardiograma deste paciente:

Caso clinico da semana - by Fábio Soares

Paciente masculino, 73 anos, HAS, DLP, admitido na unidade de emergência com IAM com supra ST de parede anterior com início há >24h, porém com recorrência de dor. CATE evidenciando lesão de DA 90% em 1/3 proximal com fluxo TIMI 2. Realizado PTCA de DA com stent convensional. Ecocardiograma realizado 12 horas apos o procedimento evidencia:

O Teste ergométrico pede passagem - by DERC

Para todos os cardiologistas e interessados em Ergometria, segue um artigo da Revista do DERC sobre a polêmica do Segmento ST com ascensão lenta: Isquêmico em quem?

http://departamentos.cardiol.br/sbc-derc/revista/2012/18-1/pdf/Rev18-1a-polemica.pdf

PARTNER A: Even mild paravalvular leaks linked with higher mortality at two years - by the Heart

Chicago, IL (updated) - Paravalvular leaks—a phenomenon virtually unheard of in the surgical valve replacement era—have truly been propelled into the limelight today, with the presentation of two-year results from the PARTNER A transcatheter aortic-valve intervention (TAVI) trial [1]. At two years, rates of death from any cause were not statistically different between transcatheter aortic-valve replacement (TAVR) and surgical valve replacement, but paravalvular regurgitation was more common after TAVR than surgery. And strikingly, even mild paravalvular regurgitation was associated with increased late mortality.

Dr Susheel Kodali (Columbia University, New York, NY) presented the two-year results here at the American College of Cardiology (ACC) 2012 Scientific Sessions; they were published online simultaneously in the New England Journal of Medicine. One-year results from the trial debuted at last year's ACC meeting, as reported at the time by heartwire.

"TAVR should be considered an alternative to surgery with similar mortality and clinical benefits," Kodali said this morning. "Periprocedural stroke concerns after TAVR have diminished with longer follow-up, and TAVR valve hemodynamics have remained stable, although periprocedural [aortic regurgitation] (even mild) has emerged as a predictor of late mortality."

Co-principal investigator, Dr Craig Smith (Columbia University), commenting on the two-year results for heartwire, acknowledged: "The paravalvular-leak findings were a surprise. Of the concerns dogging TAVR, paravalvular leak was the one for which two answers were given: one, it will become less frequent with time, experience, and modifications in design; and, two, it doesn't appear to matter anyway. For stroke and vascular complications, [the second explanation] clearly never applied.  We're back to number one alone for paravalvular leak, which shouldn't surprise us."

Kodali called the lack of difference in mortality and stroke the "most important" news from the two-year results but acknowledged that the finding that mild regurgitation is linked with mortality is "clearly interesting" and new. "What we've identified is a potential target in terms of improving on this procedure," he told heartwire. The procedure will continue to evolve, he pointed out, and a wider range of valve sizes, better recognition of patient characteristics, better imaging techniques will all help reduce the incidence of aortic regurgitation, he said. "This is a new procedure, being performed by inexperienced operators, going up against a decades-old therapy in the hands of the best surgeons," Kodali added. He believes the paravalvular findings "are not going to dampen enthusiasm for TAVI. If anything, this will motivate us to improve on these procedures and these devices."

PARTNER A: Deaths, strokes at two years

Between years one and two in the PARTNER A cohort, 32 more patients died in the TAVR group and 25 in the surgery group, with no statistical differences in deaths from any cause or from cardiovascular causes. For strokes, the end point that drove much of the conversation after one-year results were reported, an additional eight strokes occurred, four in each group. Two transient ischemic attacks (TIAs) occurred in year 2 among TAVI-treated patients as compared with just one in the surgery group, yielding an overall neurological event rate that was higher in the TAVR group than in the surgery group, reaching borderline statistical significance. For strokes alone, however, no significant differences were seen between groups at two years. By year 2, 19 patients treated surgically received a new pacemaker, compared with 23 in the TAVR group, a statistically insignificant difference.

Mortality was higher in the transapically treated patients than in the transfemorally treated patients, but Kodali stressed to a morning press conference that the trial was not powered to compare these groups, and the transapical group included the "learning-curve experience." And Dr Robert Guyton (Emory School of Medicine, Atlanta, GA), a surgeon and trial investigator, pointed out that in patients in the continued-access program (CAP) registry, which now includes over 800 patients treated via a transapical approach, mortality rates have come down. "As experienced developed, mortality actually ended up being numerically lower than in the transfemoral arm . . . and stroke rate was dramatically reduced, to less than 3%, which is one of the lowest stroke rates reported" in transcatheter trials.

Paravalvular regurgitation in the spotlight

The finding from PARTNER A year 2 that is raising eyebrows here today is the paravalvular-regurgitation data. Moderate to severe paravalvular regurgitation has already been identified as a predictor of mortality among TAVR-treated patients, but as Leon said in an interview with heartwire, this is the first time mild regurgitation has been linked with a higher death rate, and within a prospective, multicenter, randomized clinical trial, with independent core-lab echocardiographic review. "The effect of aortic regurgitation on mortality was proportional to the severity of the regurgitation, but even mild aortic regurgitation was associated with increased rate of late deaths," Kodali et al write.

Aortic regurgitation	None/trace	Mild	Moderate/severe	P (log rank)
1-y mortality (%)	14.5	29.2	29.5	<0.001
2-y mortality (%)	24.8	39.2	41.1	<0.001

Commenting on the paravalvular-regurgitation data, Dr Robert Bonow (Northwestern University, Chicago, IL) pointed out that moderate to severe paravalvular regurgitation has emerged as an important, possibly even the most important predictor of mortality in TAVI-treated patients. In patients who undergo surgical valvular replacement, the rate of moderate to severe aortic regurgitation is typically less than 1%. "Here you have 40% of TAVR-treated patients with mild aortic regurgitation, and another 10% with moderate to severe aortic regurgitation, so 50% of patients have mild regurgitation or greater—that's a potential Achilles heel."

Speaking with heartwire, senior author on the study, Dr Martin Leon (Columbia University), agreed but, like Kodali, sees a silver lining: "This is an important observation, but I would put it in perspective. If you look at overall mortality between surgery and TAVR, the rates are identical, and in no subgroup is overall mortality different," Leon told heartwire. "We're thinking paravalvular leak can be treated or prevented, and there's clear evidence that there was valve undersizing in PARTNER that we think can be corrected using postdilatation if done selectively and carefully. If you can reduce the incidence of paravalvular leak down to 'none or trace,' you could potentially reduce mortality by half."

And looking at mortality among patients with no paravalvular regurgitation vs patients with mild to severe paravalvular regurgitation, mortality rates were halved, he noted. "This suggests that this should become a very aggressive target, and new technology, improved procedure characteristics, and better sizing of the devices—those all may be important in reducing mortality as compared with surgery," Leon said.

Room to expand

Dr Craig Smith

Bonow and Smith tended to agree with Leon and Kodali, with Smith, a surgeon, predicting that "the frequency of paravalvular leak will decrease with experience and will not be a major impediment. Design may also play a role but is a more complicated and theoretical discussion."

Bonow, likewise, said that interventionalists he's spoken with are now doing everything they can to make sure they "fix" a paravalvular leak when they see moderate to severe regurgitation, by reexpanding the device or even using a valve-in-valve procedure. But to date, he says, operators haven't been overly concerned about mild regurgitation—that should likely change.

Already, speculation is mounting as to whether the paravalvular data might be one reason the FDA has not yet announced a date for its advisory committee to review the PARTNER A data, where the sponsor is seeking to extend the indication for TAVR to patients who are also eligible for surgery.

"In a regulatory environment sensitized by lead fractures, failing steel hip prostheses, and other postapproval embarrassments, this is sure to be noticed and will probably slow approval in young, low-risk populations until long term success is better understood," Smith speculated.