AHA2012：ICD电击会增加患者焦虑程度和死亡率

　　洛杉矶——在美国心脏协会(AHA)2012科学年会上，克利夫兰医院的Jason George医生及其同事报告称，当患者受到置入式心脏复律除颤器(ICD)的电击时，其焦虑水平会上升，死亡率也会增加。

　　George博士等人在这项前瞻性研究中纳入了2009年3月~2010年12月美国克利夫兰医院收治的704例连续ICD置入患者，所有患者均在入选研究至少4周以前接受了ICD置入。贝克焦虑量表(BAI)的患者评价结果显示，得分≥8分者占36%，8分为轻度焦虑的阈值。在239例(占所有接受了评估的患者的34%)至少经历过1次电击的患者中，BAI平均得分为8.3分，而在另外465例患者中仅为6.7分，提示没有经历过电击的患者焦虑程度很轻。这两个亚组在BAI平均得分上的差异具有统计学意义。

　　在BAI评分前4周内经历过电击的患者中，平均得分为11.2分，而在评分前4周内没有经历过电击的患者中，BAI平均得分仅为7.1分，差异也有统计学意义。分析还表明，抑郁与ICD电击之间没有明显的相关性。

　　研究者总结道，这项焦虑分析表明，患者的焦虑水平与ICD电击的出现、患者接收到的电击总数以及近期电击发生的时间显著相关。研究者还指出，36%的ICD患者都存在轻度或轻度以上的焦虑，这提示“关注焦虑可能对于经历过任何一种电击的患者会所有帮助”，尤其是对于经历过多次电击或者近期经历过电击的患者。

　　George博士等人开展的另一项死亡率分析纳入了来自克利夫兰医院的连续690例ICD置入者，对其进行了前瞻性随访。在为期2.8年的中位随访期内，共有8.3%的患者死亡。分析显示，只经历过不当电击的患者、最多经历过2次电击的患者以及没有经历过电击的患者其死亡率大致相同，都在6%左右。随访期间只经历过恰当电击的患者其死亡率约为11%，既经历过恰当电击又经历过不当电击的患者其死亡率最高，达到了22%左右。

　　总的来看，死亡患者平均经历过5.4次电击，而没有死亡的患者平均经历过2.3次电击。接受了≥3次电击的患者死亡率为15%，而只接受了3次以下电击的患者的死亡率仅为6%，差异有统计学意义。George博士及其同事总结道：“上述结果表明，电击可能是死亡的一个次要标志物，而非导致死亡的主要原因。”

　　研究者补充道，死亡率随着电击次数的增加而增加，这验证了之前其他研究所观察到的结果；但与先前的研究不同，这项研究只在经历了恰当电击的患者中发现了这一相关性。这些研究结果提出了这样一个疑问：旨在抑制电击的措施是否能提高患者的生存率？

　　George博士及其同事声明无相关利益冲突。

By: MITCHEL L. ZOLER, Cardiology News Digital Network

LOS ANGELES – When patients receive shocks from implantable cardioverter defibrillators their anxiety level rises, and so does their mortality rate.

Measured anxiety levels significantly correlated with the occurrence of shocks from ICDs, the total number of shocks that patients received, and how recently the shocks occurred, in a prospective study of 704 consecutive ICD recipients from one U.S. center, Dr. Jason George and his associates reported in a poster at the annual scientific sessions of the American Heart Association.

In addition, patients who received three or more shocks had a 15% mortality rate during a median of 2.8 years of follow-up, significantly more than the 6% rate among patients who received fewer than three shocks, based on prospective follow-up of 690 consecutive ICD recipients at the same center, said Dr. George, a physician at the Cleveland Clinic.

Shocks from an ICD can raise a patient's anxiety level and mortality rate.

The substantial 36% prevalence of mild or greater anxiety found in these ICD patients suggested that "attention to anxiety may help patients who experience any type of shock," and may be especially helpful to patients who received several shocks or recent shocks, the researchers said.

The link found between higher shock number and increased mortality confirms observations previously made in other studies, they added, although unlike prior reports, the current study found this link only for appropriate shocks. The finding raises the question of whether measures designed to suppress shocks might boost patient survival, they said.

The anxiety analysis included patients who received an ICD more than 4 weeks prior to enrollment into the study at the Cleveland Clinic between March 2009 and December 2010. Patient assessment with the Beck Anxiety Inventory (BAI) showed that 36% had a score of at least 8, the threshold for mild anxiety. The average BAI score among the 239 patients (34% of the patients assessed) who had ever received at least one shock was 8.3, while the average score among the other 465 patients was 6.7, showing that nonshocked patients had minimal anxiety. The difference in average scores between these two subgroups was statistically significant, the investigators reported.

Among patients who had received a shock within 4 weeks of BAI scoring, the average score was 11.2, while among patients who had not received a shock within the prior 4 weeks the average BAI score was 7.1, also a significant difference. The analysis also showed that depression was not significantly associated with shocks.

The mortality analysis performed by Dr. George and his associates at the Cleveland Clinic included 690 patients followed prospectively after they received an ICD between March 2009 and December 2010. During follow-up, a total of 8.3% of the patients died. This analysis showed that patients who received only inappropriate shocks, patients who received two or fewer shocks, and those who received no shocks each had about the same mortality rate, about a 6% rate during the median 2.8 years of follow-up. Patients who received only appropriate shocks had about an 11% mortality rate during follow-up, and patients who received both appropriate and inappropriate shocks had the highest mortality rate, about 22%.

Overall, patients who died received an average of 5.4 shocks, while those who did not die received an average of 2.3 shocks. "These findings suggest that shocks may be a secondary marker of mortality rather than a primary cause of mortality," Dr. George and his associates concluded.

Dr. George and his associates said that they had no disclosures.