Manufacturers of artificial hearts will take heart in the report last month by the Centers for Medicare & Medicaid Services (CMS; Atlanta) that it will re-examine its policy that denies reimbursement for the devices. CMS said that the agency "has a long-standing non-coverage policy regarding the use of artificial hearts" for both destination therapy (DT) and as a bridge to transplant (BTT). It said that part of the reason for the difference in coverage compared to ventricular assist devices (VADs), is that many patients on a VAD have some hope of recovering heart function.

The statement came in response to a petition filed by SynCardia (Tucson, Arizona), maker of the CardioWest temporary artificial heart, which offers the argument that since its device is temporary, it can be used not only to support the failing heart but help it recover.

Three years ago, CMS created a diagnosis-related group (DRG) into which artificial hearts could fit, DRG 103, but up to now the agency has not been persuaded as to the necessity and appropriateness for issuing a national coverage decision (NCD).

The CardioWest relies on externally provided pneumatic drivers to keep the pumping mechanism going, which limits patient mobility. FDA issued SynCardia a PMA for the device in 2004 with the BTT application, and the company is currently working on a portable pneumatic unit that can be toted on a two-wheel cart, similar to those used to haul briefcases and laptop computer cases. Should the firm get a PMA from the agency for the portable pneumatic unit, it will have a substantial impact on patient mobility.

Abiomed (Danvers, Massachusetts), also participates in this sector via its AbioCor artificial heart, which has won a human device exemption, won in 2006, limiting its use to no more than 4,000 implantations a year. Unlike the SynCardia TAH-t (Total Artificial Heart-temporary), the AbioCor is a fully implantable device. Any device sold under the HDE is restricted to sales of 4,000 units a year, the regulatory ceiling for the number of per-year diagnoses applicable to the device under the HDE protocol.

Abiomed's president, Mike Minogue, has said that Abiomed has no plan to pursue a PMA for the AbioCor, although the option is still open for its successor, the AbioCor II, which is in development, and roughly 30% smaller than its antecedent. The AbioCor II should fit into almost all men and half of the women in the U.S.

Neither the CardioWest heart nor the AbioCor is cheap. Cost for the Cardio West runs to $106,000, while the AbioCor has a $250,000 price tag. Both of these companies have argued that the alternative interventions for keeping a patient alive in the face of total heart failure — primarily drug therapy — run up huge costs.

CMS said that it is "interested in public comments that relate to" three areas of interest, including peer review literature on "artificial hearts when used for bridge to transplantation or destination therapy" and on hospital requirements, including staffing, equipment, experience, transplant status and so on.

CMS's current policy does not prevent the adoption of local coverage decisions (LCDs) by local contractors. And at least one contractor, Blue Cross of California (Woodland Hills, California), reportedly has issued an LCD of medically necessity and reasonableness for the CardioWest TAH-t.

Less pacing may lower risk of AF for some patients with pacemakers

Reducing unnecessary pacing to the heart's lower right chamber in patients with dual chamber pacemakers lowers the risk of developing atrial fibrillation (AF), according to a study funded by Medtronic (Minneapolis) and published in the New England Journal of Medicine. The results showed that reducing pacing to the heart's lower right chamber to less than 10% in dual chamber pacemaker patients lowered the relative risk of developing AF by 40% in a trial of more than 1,000 patients with sinus node disease (SND). SND, the most common reason for pacemaker implantation, is characterized by delayed or failed conduction between the sinus node and the atria, the heart's upper chambers.

The Search AV Extension and Managed Ventricular Pacing for Promoting Atrioventricular Conduction (SAVE PACe) trial is said to be the first study to demonstrate a clear superiority of newer forms of dual chamber pacing for sinus node disease versus older pacemaker technology. Michael Sweeney, MD, lead investigator of SAVE PACe, told Cardiovascular Device Update that the results of the study should have a "very significant impact on the public health issue" of AF.

The first device used in the trial was the Medtronic Kappa family of pacemakers, which was replaced with the newer EnRhythm pacing system with the Managed Ventricular Pacing feature, Sweeney said. The trial's objective was to demonstrate that dramatically reducing unnecessary right ventricular pacing could reduce the development of persistent AF.

The study was developed in 2002, began enrolling patients in 2003, and was terminated in December 2006 after an interim analysis revealed that patients not using the newer forms of dual chamber pacing from Medtronic showed a 1.8 greater risk of developing persistent AF than those using them. This difference was highly statistically significant, the company said.

Sweeney, associate professor of medicine at Harvard Medical School (Boston) and an electrophysiologist at Brigham and Women's Hospital (Boston), said that the outcome of the study was not a great surprise but that it was interesting to see how broadly applicable it can be among SND patients who receive pacemakers. "The reduction of relative risk of atrial fibrillation was observed across all clinically relevant population subgroups . . . every group of patients that we could parcel out within the study population had this benefit," Sweeney said.

AF "is a huge public health program . . . the vast majority of patients who receive a pacemaker for sinus node disease experience atrial fibrillation upon follow-up," Sweeney said. "It absolutely dominates the care and management of these patients."

After an average of 1.7 years in the study, 68 patients who received conventional dual chamber pacing developed persistent AF (12.7%), compared with 42 patients (7.9%) who received dual chamber minimal ventricular pacing, which minimizes unnecessary pacing to the right ventricle of the heart. Mortality was similar in the two patient groups, but heart failure hospitalizations were more than 50% lower for the group of patients with dual chamber minimal ventricular pacing (3.2% vs. 7.3% for those who received conventional dual chamber pacing).

"It's important because it targets atrial fibrillation and the overlap with need for pacemaker therapy," Sweeney told CDU. He said that there is a fair amount of retrospective evidence linking ventricular pacing with AF, but that the SAVE PACe trial is unique because it is the first study that validates the concept on a larger scale. He said, "they either have not published evidence that they can deliver on that promise, or the evidence they have published is inferior by comparison."

Because of a lack of understanding, Sweeney said many pacemakers on the market already have these features but that the technology is not being exploited to achieve the goal of reducing the risk of AF. This demonstrates, he said, "that pacemakers, just like pharmacologic therapy, in addition to being effective for their intended goal, can have side effects."

AHRQ confirms trend: more intervention, less CABG

The Agency for Healthcare Research and Quality (Washington) last month released data from its Hospital Cost and Utilization Project (HCUP) for 2005, the data indicating that not only is hospital care not getting any cheaper, but that overall costs are growing despite the decreasing use of more costly coronary artery bypass grafting (CABG) and increasing use of less costly angioplasty for treatment of congestive heart disease.

Vincent Bufalino, MD, an associate professor of medicine at the Stritch School of Medicine at Loyola University (Chicago), told Cardiovascular Device Update that report data showing heart attack (infarction) as the fifth most common diagnosis for men but ranking only number 20 for women is not surprising. "Men get heart disease earlier than women, and get more clear-cut cases of infarction."

The HCUP report says that bypass procedures are down by a third since 1997 and angioplasties have doubled since 1993. Bufalino said that single-vessel bypasses are becoming rare. "The number of single-vessel bypasses is down to trivial," he said, adding that patients who are back for a second procedure are often not good candidates for a second thoracic procedure.

"If you have a recurrence 12 years later, it's usually in one spot, and we can now get at single isolated problems." However, such patients are also often less able to withstand a full opening of the chest wall. Such a procedure is often complicated because scar tissue "gets almost rock-like," Bufalino said, adding that "surgeons talk about chipping down" through scar tissue just to get to the heart.

"There's an increased migration toward two-vessel angioplasty from a couple of years ago," which he said is "very much driven by" patients' natural aversion to more invasive procedures.

There was once a substantial difference in awareness of heart disease by sex, but Bufalino said that data indicated that women are now more aware of heart disease, with 60% to 70% of women having a clear understanding of their risk, a jump of about a factor of 10 from several decades ago. "I think men are aware and women are aware for their men."

However, he indicated that reluctance to see the doctor is not just for men anymore. "Wives are sending their husbands but are often reluctant to go to a doctor" themselves. Bufalino also said he felt that publicity concerning breast cancer has somewhat overshadowed heart disease for women despite the fact that heart disease kills more women.

Bufalino said that the numbers for heart disease are quite encouraging. "I think we should be celebrating the success" of improvements to heart care in the past three decades, he said. "The way we practiced in 1977, if you came to the hospital with a heart attack, about 30% died in the hospital," a number he said is down to 3%. In 1977, a patient who checked in with a heart attack could count on spending two weeks in the hospital and was probably out of work for six months.

"If you come to the hospital today, within 90 minutes, you're in the cath lab opening the arteries," he said, and that most patients are out of the hospital in three or four days and back to work in two weeks.

With the exception of the development of vaccines, he called developments in the cath lab "probably the single most successful area of medicine." The report also suggests that community hospitals are busier places than in times gone by. The data indicates that between 1997 and 2005, the number of community hospitals dropped by 124, from 5,060 to 4,963, but the volume of hospital stays rose by 4.5 million over that same period, from 34.7 million to 39.2 million, an increase of roughly 13%. The duration of stays fell during that same period, from 4.9 to 4.6 days, but not enough to offset the increase in stays.

Additionally, the HCUP report says that "the average cost per hospital inpatient stay in 2005 was $7,900, up an average of 5.7% annually since 1997."

The HCUP numbers indicate that although the average duration of hospital stays fell by 4%, the incidence of pressure sores is up 76% between 1993 and 2005. Bufalino said that age has a lot to do with this phenomenon. "The length of stays is down, and the morbidity is less and there are fewer complications," he said, but "the real issue for us is that folks are older."

"I have three dozen patients in their 90s," which is obviously a change from yesteryear. "It was pretty rare to have a patient in their 90s back in the old days." These patients tend to be bedridden for longer stretches and are less resistant to bed sores.

Optimal techniques for CTA scanning of children are lacking

Cardiac-gated computed tomography angiograph (CTA) radiation doses can vary and can be as high as 28.4 mSv (10 times the annual natural background radiation) in children, according to a recent study conducted by researchers from Duke University Medical Center (DUMC; Durham, North Carolina) and Stanford University Medical Center (Palo Alto, California).

"The results of this investigation support that coronary CTA doses vary substantially with different parameters and can provide very high radiation doses to children when adult-type parameters are utilized," said Hollingsworth. "Optimal techniques in children have yet to be developed and the results of this study show that gated CTA should be used cautiously in the pediatric population while further evaluation of newer techniques (modulation), applications and outcomes are evaluated," she said.

"This investigation evaluated the potential radiation dose of coronary CT angiography in pediatric patients," said Caroline Hollingsworth, MD, of DUMC, lead author. "Since often adult technologies and techniques are simply applied to children, we were interested in assessing what the dose could be," she said.

"Technical advances in multi-detector CT angiography have lead to increased utilization of this technology for evaluation of the coronary arteries in adults. However, this technology lacks systematic assessment in children," said Hollingsworth. "Due to concerns for potentially large radiation doses from this type of CT evaluation, we were interested in assessing standard gated coronary CTA techniques in a pediatric phantom. Dosimetry information is important since optimal techniques for this type of coronary assessment are still under evolution as this technology becomes increasingly utilized," she said.

For the study, an ECG-gated cardiac CTA-simulating scanning of the heart was performed on a phantom of a 5-year-old using a 16-MDCT scanner. The highest doses were of the breast (3.5-12.6 cGy), lung (3.3-12.1 cGy) and bone marrow (1.7-7.6 cGy). To put these numbers into perspective, 12 cGy is equivalent to about 50 two-view screening mammograms.

The full results of this study appeared in the July issue of the American Journal of Roentgenology, published by the American Roentgen Ray Society (Leesburg, Virginia).