cotto 2010-5-18 11:37
二尖主動脈瓣患者發生腦動脈瘤風險增加
作者：Allison Gandey
出處：WebMD醫學新聞
May 4, 2010 — 研究者們提醒，有最常見先天性心臟缺損的患者，也比較容易發生顱內動脈瘤。
他們報告，在他們的新研究中，將近10%的二尖主動脈瓣患者有動脈瘤。
主要作者加州洛杉磯Cedars-Sinai醫學中心的Wouter Schievink醫師在一篇新聞稿中表示，當需要更多研究來確認這項結果時，這些發現也顯示有二尖主動脈瓣患者發生腦部動脈瘤的風險顯著增加。
高達2%民眾在出生時有先天性心臟缺損，因此研究者們認為這項研究的意義是很重要的。
他們的成果發表在5月4日的神經學期刊。研究者們進行一項共291位患者的病歷控制研究。這些患者接受腦部核磁共振或電腦斷層血管攝影。
研究者們報告，二尖主動脈瓣患者發生顱內動脈瘤的頻率與其他風險較高的全身性疾病，例如染色體顯性多囊性腎臟疾病、或是主動脈窄縮，兩者的風險是相當的。
表格 顱內動脈瘤的發生率
[table][tr][td][align=center]病患族群 [/align][/td][td][align=center]動脈瘤個數（ % ） [/align][/td][td][align=center]95% 信賴區間 [/align][/td][td][align=center][i]P 值 [/i][/align][/td][/tr][tr][td][align=center]二尖主動脈瓣患者（ n = 61 ） [/align][/td][td][align=center]6 (9.8) [/align][/td][td][align=center]2.4 – 17.3 [/align][/td][td][align=center].0012 [/align][/td][/tr][tr][td]控制組（ n = 291 ）
[/td][td][align=center]3 (1.1) [/align][/td][td][align=center]0 – 2.2 [/align][/td][td][align=center].0012 [/align][/td][/tr][/table]
顱內動脈瘤的危險因子，例如女性與高齡，在控制組是很常見的（P=0.02與P=0.003）。
Schievink醫師報告，二尖主動脈瓣患者，其年齡、性別、吸菸、高血壓、喝酒、主動脈半徑或是主動脈窄縮的頻率，在那些有動脈瘤與沒有動脈瘤的患者身上並無顯著差異。
Schievink醫師指出，二尖主動脈瓣的問題傾向於發生在家族之間。他表示，部分病患已經證實有NOTCH1的突變，但是這樣的缺失在基因上可能是不盡相同的。
基因因素顯然是顱內動脈瘤相關因子。染色體9q部位的單一核苷酸多型性已經被證實與動脈瘤或其他動脈疾病有關。
在全基因組關連性研究中，由康乃狄克紐哈芬市耶魯大學的Kaya Bilguvar醫師領導的研究團隊，將染色體2q與8q加入到這個清單中。他們報告造成顱內動脈瘤的勝算比從1.24增加到1.36（Nat Genet. 2008;40:1472-1477）。
Schievink醫師承認他的新研究樣本數目太小，目前並無法達成任何結論，且呼籲應該進行更多研究。
研究者們表示沒有相關資金上的往來。
Bicuspid Aortic Valve Patients at Increased Risk for Brain Aneurysm
By Allison Gandey
Medscape Medical News
May 4, 2010 — Patients with the most common congenital heart defect are also more likely to develop an intracranial aneurysm, warn researchers.
They report close to 10% of bicuspid aortic valve patients in their new study had an aneurysm.
"While more research needs to be done to confirm the results, these findings show a significant increased risk of brain aneurysms in people with bicuspid aortic valves," lead investigator Wouter Schievink, MD, from Cedars-Sinai Medical Center in Los Angeles, California, said in a news release.
Up to 2% of the population is born with the congenital heart defect, so the investigators suggest the implications of this study could be important.
Their work appears in the May 4 issue of Neurology. Investigators conducted a case-control study of 291 people. Patients underwent magnetic resonance or computed tomography angiography of the brain.
The researchers report the frequency of intracranial aneurysm among bicuspid aortic valve patients is similar to that found in patients with other systemic disorders that carry an increased risk, such as autosomal dominant polycystic kidney disease or coarctation of the aorta.
Table. Rate of Intracranial Aneurysms
[table][tr][td][b]Population[/b] [/td][td][b]No. (%) of Aneurysms[/b] [/td][td][b]95% Confidence Interval, %[/b] [/td][td][b][i]P[/i] Value[/b] [/td][/tr][tr][td]Bicuspid aortic valve patients (n = 61)[/td][td]6 (9.8)[/td][td]2.4 – 17.3[/td][td].0012[/td][/tr][tr][td]Control patients (n = 291)[/td][td]3 (1.1)[/td][td]0 – 2.2[/td][td].0012[/td][/tr][/table]
Risk factors for intracranial aneurysm, such as female sex and advanced age, were more common in the control group (P = .02 and P = .003).
In the bicuspid aortic valve patients, Dr. Schievink reports no significant differences in age, sex, smoking, arterial hypertension, alcohol use, aortic diameter, or frequency of aortic coarctation between those who had an aneurysm and those who did not.
Dr. Schievink points out that bicuspid aortic valve problems tend to cluster in families. He notes that mutations in NOTCH1 have been reported in some, but the defect is probably genetically heterogeneous.
Genetic factors also appear to factor into intracranial aneurysm. Single-nucleotide polymorphisms on the 9p locus have been linked to aneurysm and other arterial diseases.
In a genome-wide association study, investigators led by Kaya Bilguvar, MD, from Yale University in New Haven, Connecticut, added chromosomes 2q and 8q to the list. They reported increased odds ratios for intracranial aneurysm of 1.24 to 1.36 (Nat Genet. 2008;40:1472-1477).
Dr. Schievink acknowledges his new study is too small to draw any firm conclusions and calls for additional investigation.
The researchers have disclosed no relevant financial relationships.
Neurology. 2010;74:1430-1433.