患者の生存期間はPCI後よりもCABG後の方が長い

ASCERT Trial:スタディの結果、生存期間は冠動脈形成術よりも冠動脈バイパス術を施行された患者の方が長いことが示唆された
ASCERT Trial: Study suggests better survival in patients undergoing bypass surgery compared to coronary angioplasty
冠動脈バイパス術は低侵襲の経皮的冠動脈インターベンションよりも生存率を上昇させるようであるとの新たなエビデンスが示され、第61回American College of Cardiology学会で発表され、同時にNew England Journal of Medicineに掲載された。過去のいくつかのスタディにより、この2つの治療法の長期予後は同等であることが示唆されたが、バイパス手術の予後の方が良好であることを示したスタディもあった。ASCERTトライアルにおいて研究者らはAmerican College of Cardiology Foundation CathPCIデータベース、Society of Thoracic Surgeons CABGデータベース、およびU.S. Medicare請求データベースから得た患者データを組み合わせ、2004~2008年に治療を受けた冠動脈バイパス術後患者86,000人およびPCI後患者103,000人の生存率を比較した。治療後4年間の死亡率はPCIを施行された患者において冠動脈バイパス術を選択された患者よりも高かった(それぞれ20.8%および16.41%)。この結果は解析した全てのサブグループにおいて同様であった。このスタディは安定虚血性心疾患患者における血行再建術の選択決定の際の情報として役に立つだろう、と筆者らは述べている。
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Patients with coronary heart disease and their doctors have long been challenged by the decision of whether to pursue bypass surgery or opt for the less-invasive percutaneous coronary intervention (PCI). New evidence reveals bypass surgery appears to carry a higher long-term survival rate, according to research presented at the American College of Cardiology's 61st Annual Scientific Session.

The study analyzed health outcomes of 190,000 patients across the United States to compare the results of bypass surgery to those of PCI. The study found that patients who underwent PCI had a higher death rate in the first four years after treatment than those who had opted for bypass surgery (20.8 percent and 16.41 percent, respectively).

"Our study is the most general one ever done because it uses data from across the whole country. It is also much larger than any other study," said William S. Weintraub, M.D., chair of cardiology at Christiana Care Health System and the study's lead investigator. "Combining data from several large databases, we found that survival was better with coronary surgery than percutaneous coronary intervention."

Dr. Weintraub cautioned that the results do not mean bypass surgery is best for every patient. "It does push the needle toward coronary surgery, but not overwhelmingly so," said Dr. Weintraub. "When we're recommending coronary surgery to patients, even though it is a bigger intervention than PCI, we can now have a little more confidence that the decision is a good one."

While some previous studies have suggested the two treatments have similar long-term outcomes, others have also shown better outcomes with bypass surgery. Patients and doctors tend to choose the less-invasive PCI when both treatments are an option.

The study, called the ACCF and STS Database Collaboration on the Comparative Effectiveness of Revascularizaton Strategies (ASCERT), combined patient data from the American College of Cardiology Foundation CathPCI database, the Society of Thoracic Surgeons CABG database and the U.S. Medicare claims database to compare survival rates among 86,000 bypass surgery patients and 103,000 PCI patients who underwent treatment from 2004-2008.  Dr. Weintraub says that a major limitation of observational studies, such as this one, is that the groups may not have the same level of risk, and so it is possible that the worse outcomes in the PCI patients were related to these patients being sicker overall. "We used sophisticated statistics to account for different levels of risk, but there may be differences between the two groups that we could not account for," he said.

The large number of cases allowed the researchers to compare results across many subgroups.  "What was a surprise to us all was how consistent the data were no matter what analytic approach we used, and how consistent the data were across all subgroups," said Dr. Weintraub. "Survival was better with coronary surgery for all patient subgroups. This study should help inform decision making concerning the choice of revascularization in patients with stable ischemic heart disease."

This study was funded by the National Institutes of Health's National Heart, Lung and Blood Institute.

This study was simultaneously published online in the New England Journal of Medicine.